diff --git a/tools/gyp/buildbot/buildbot_run.py b/tools/gyp/buildbot/buildbot_run.py
index df1cc8ad5e..a8531258b2 100755
--- a/tools/gyp/buildbot/buildbot_run.py
+++ b/tools/gyp/buildbot/buildbot_run.py
@@ -13,7 +13,45 @@ import subprocess
 import sys
 
 
-def GypTestFormat(title, format, msvs_version=None):
+if sys.platform in ['win32', 'cygwin']:
+  EXE_SUFFIX = '.exe'
+else:
+  EXE_SUFFIX = ''
+
+
+BUILDBOT_DIR = os.path.dirname(os.path.abspath(__file__))
+TRUNK_DIR = os.path.dirname(BUILDBOT_DIR)
+ROOT_DIR = os.path.dirname(TRUNK_DIR)
+OUT_DIR = os.path.join(TRUNK_DIR, 'out')
+NINJA_PATH = os.path.join(TRUNK_DIR, 'ninja' + EXE_SUFFIX)
+NINJA_WORK_DIR = os.path.join(ROOT_DIR, 'ninja_work')
+
+
+def InstallNinja():
+  """Install + build ninja.
+
+  Returns:
+    0 for success, 1 for failure.
+  """
+  print '@@@BUILD_STEP install ninja@@@'
+  # Delete old version if any.
+  try:
+    shutil.rmtree(NINJA_WORK_DIR, ignore_errors=True)
+  except:
+    pass
+  # Sync new copy from git.
+  subprocess.check_call(
+      'git clone https://github.com/martine/ninja.git ' + NINJA_WORK_DIR,
+      shell=True)
+  # Bootstrap.
+  subprocess.check_call('./bootstrap.sh', cwd=NINJA_WORK_DIR, shell=True)
+  # Copy out ninja.
+  shutil.copyfile(os.path.join(NINJA_WORK_DIR, 'ninja' + EXE_SUFFIX),
+                  NINJA_PATH)
+  os.chmod(NINJA_PATH, 0777)
+
+
+def GypTestFormat(title, format=None, msvs_version=None):
   """Run the gyp tests for a given format, emitting annotator tags.
 
   See annotator docs at:
@@ -23,12 +61,27 @@ def GypTestFormat(title, format, msvs_version=None):
   Returns:
     0 for sucesss, 1 for failure.
   """
+  if not format:
+    format = title
+
+  # Install ninja if needed.
+  # NOTE: as ninja gets installed each time, regressions to ninja can come
+  # either from changes to ninja itself, or changes to gyp.
+  if format == 'ninja':
+    try:
+      InstallNinja()
+    except Exception, e:
+      print '@@@STEP_FAILURE@@@'
+      print str(e)
+      return 1
+
   print '@@@BUILD_STEP ' + title + '@@@'
   sys.stdout.flush()
-  buildbot_dir = os.path.dirname(os.path.abspath(__file__))
-  trunk_dir = os.path.dirname(buildbot_dir)
-  root_dir = os.path.dirname(trunk_dir)
   env = os.environ.copy()
+  # TODO(bradnelson): remove this when this issue is resolved:
+  #     http://code.google.com/p/chromium/issues/detail?id=108251
+  if format == 'ninja':
+    env['NOGOLD'] = '1'
   if msvs_version:
     env['GYP_MSVS_VERSION'] = msvs_version
   retcode = subprocess.call(' '.join(
@@ -38,7 +91,7 @@ def GypTestFormat(title, format, msvs_version=None):
        '--format', format,
        '--chdir', 'trunk',
        '--path', '../scons']),
-      cwd=root_dir, env=env, shell=True)
+      cwd=ROOT_DIR, env=env, shell=True)
   if retcode:
     # Emit failure tag, and keep going.
     print '@@@STEP_FAILURE@@@'
@@ -49,17 +102,23 @@ def GypTestFormat(title, format, msvs_version=None):
 def GypBuild():
   # Dump out/ directory.
   print '@@@BUILD_STEP cleanup@@@'
-  print 'Removing out/ ...'
-  shutil.rmtree('out', ignore_errors=True)
+  print 'Removing %s...' % OUT_DIR
+  shutil.rmtree(OUT_DIR, ignore_errors=True)
+  print 'Removing %s...' % NINJA_WORK_DIR
+  shutil.rmtree(NINJA_WORK_DIR, ignore_errors=True)
+  print 'Removing %s...' % NINJA_PATH
+  shutil.rmtree(NINJA_PATH, ignore_errors=True)
   print 'Done.'
 
   retcode = 0
   if sys.platform.startswith('linux'):
-    retcode += GypTestFormat('scons', format='scons')
-    retcode += GypTestFormat('make', format='make')
+    retcode += GypTestFormat('ninja')
+    retcode += GypTestFormat('scons')
+    retcode += GypTestFormat('make')
   elif sys.platform == 'darwin':
-    retcode += GypTestFormat('xcode', format='xcode')
-    retcode += GypTestFormat('make', format='make')
+    retcode += GypTestFormat('ninja')
+    retcode += GypTestFormat('xcode')
+    retcode += GypTestFormat('make')
   elif sys.platform == 'win32':
     retcode += GypTestFormat('msvs-2008', format='msvs', msvs_version='2008')
     if os.environ['BUILDBOT_BUILDERNAME'] == 'gyp-win64':
diff --git a/tools/gyp/gyptest.py b/tools/gyp/gyptest.py
index 0cf38b15c5..e8bf482d99 100755
--- a/tools/gyp/gyptest.py
+++ b/tools/gyp/gyptest.py
@@ -212,7 +212,7 @@ def main(argv=None):
       'win32':    ['msvs'],
       'linux2':   ['make', 'ninja'],
       'linux3':   ['make', 'ninja'],
-      'darwin':   ['make', 'xcode'],
+      'darwin':   ['make', 'ninja', 'xcode'],
     }[sys.platform]
 
   for format in format_list:
diff --git a/tools/gyp/pylib/gyp/common.py b/tools/gyp/pylib/gyp/common.py
index b44b0956f7..97594cd5d6 100644
--- a/tools/gyp/pylib/gyp/common.py
+++ b/tools/gyp/pylib/gyp/common.py
@@ -344,6 +344,18 @@ def WriteOnDiff(filename):
   return Writer()
 
 
+def GetFlavor(params):
+  """Returns |params.flavor| if it's set, the system's default flavor else."""
+  flavors = {
+    'darwin': 'mac',
+    'sunos5': 'solaris',
+    'freebsd7': 'freebsd',
+    'freebsd8': 'freebsd',
+  }
+  flavor = flavors.get(sys.platform, 'linux')
+  return params.get('flavor', flavor)
+
+
 # From Alex Martelli,
 # http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52560
 # ASPN: Python Cookbook: Remove duplicates from a sequence
diff --git a/tools/gyp/pylib/gyp/generator/dump_dependency_json.py b/tools/gyp/pylib/gyp/generator/dump_dependency_json.py
index ada1d35b07..1e0900a231 100644
--- a/tools/gyp/pylib/gyp/generator/dump_dependency_json.py
+++ b/tools/gyp/pylib/gyp/generator/dump_dependency_json.py
@@ -25,21 +25,10 @@ for unused in ['RULE_INPUT_PATH', 'RULE_INPUT_ROOT', 'RULE_INPUT_NAME',
   generator_default_variables[unused] = ''
 
 
-def GetFlavor(params):
-  """Returns |params.flavor| if it's set, the system's default flavor else."""
-  flavors = {
-    'darwin': 'mac',
-    'sunos5': 'solaris',
-    'freebsd7': 'freebsd',
-    'freebsd8': 'freebsd',
-  }
-  flavor = flavors.get(sys.platform, 'linux')
-  return params.get('flavor', flavor)
-
-
 def CalculateVariables(default_variables, params):
   generator_flags = params.get('generator_flags', {})
-  default_variables['OS'] = generator_flags.get('os', GetFlavor(params))
+  default_variables['OS'] = generator_flags.get(
+      'os', gyp.common.GetFlavor(params))
 
 
 def CalculateGeneratorInputInfo(params):
diff --git a/tools/gyp/pylib/gyp/generator/make.py b/tools/gyp/pylib/gyp/generator/make.py
index 31c016e4c8..87ad79a675 100644
--- a/tools/gyp/pylib/gyp/generator/make.py
+++ b/tools/gyp/pylib/gyp/generator/make.py
@@ -55,25 +55,13 @@ generator_supports_multiple_toolsets = True
 generator_wants_sorted_dependencies = False
 
 
-def GetFlavor(params):
-  """Returns |params.flavor| if it's set, the system's default flavor else."""
-  flavors = {
-    'darwin': 'mac',
-    'sunos5': 'solaris',
-    'freebsd7': 'freebsd',
-    'freebsd8': 'freebsd',
-  }
-  flavor = flavors.get(sys.platform, 'linux')
-  return params.get('flavor', flavor)
-
-
 def CalculateVariables(default_variables, params):
   """Calculate additional variables for use in the build (called by gyp)."""
   cc_target = os.environ.get('CC.target', os.environ.get('CC', 'cc'))
   default_variables['LINKER_SUPPORTS_ICF'] = \
       gyp.system_test.TestLinkerSupportsICF(cc_command=cc_target)
 
-  flavor = GetFlavor(params)
+  flavor = gyp.common.GetFlavor(params)
   if flavor == 'mac':
     default_variables.setdefault('OS', 'mac')
     default_variables.setdefault('SHARED_LIB_SUFFIX', '.dylib')
@@ -2722,7 +2710,7 @@ def CopyTool(flavor, out_path):
 
 def GenerateOutput(target_list, target_dicts, data, params):
   options = params['options']
-  flavor = GetFlavor(params)
+  flavor = gyp.common.GetFlavor(params)
   generator_flags = params.get('generator_flags', {})
   builddir_name = generator_flags.get('output_dir', 'out')
   android_ndk_version = generator_flags.get('android_ndk_version', None)
diff --git a/tools/gyp/pylib/gyp/generator/ninja.py b/tools/gyp/pylib/gyp/generator/ninja.py
index b307da650d..193f295a55 100644
--- a/tools/gyp/pylib/gyp/generator/ninja.py
+++ b/tools/gyp/pylib/gyp/generator/ninja.py
@@ -13,18 +13,15 @@ import sys
 import gyp.ninja_syntax as ninja_syntax
 
 generator_default_variables = {
-  'OS': 'linux',
-
   'EXECUTABLE_PREFIX': '',
   'EXECUTABLE_SUFFIX': '',
   'STATIC_LIB_PREFIX': '',
   'STATIC_LIB_SUFFIX': '.a',
   'SHARED_LIB_PREFIX': 'lib',
-  'SHARED_LIB_SUFFIX': '.so',
 
   # Gyp expects the following variables to be expandable by the build
   # system to the appropriate locations.  Ninja prefers paths to be
-  # known at compile time.  To resolve this, introduce special
+  # known at gyp time.  To resolve this, introduce special
   # variables starting with $! (which begin with a $ so gyp knows it
   # should be treated as a path, but is otherwise an invalid
   # ninja/shell variable) that are passed to gyp here but expanded
@@ -103,7 +100,7 @@ def InvertRelativePath(path):
 #   to the input file name as well as the output target name.
 
 class NinjaWriter:
-  def __init__(self, target_outputs, base_dir, build_dir, output_file):
+  def __init__(self, target_outputs, base_dir, build_dir, output_file, flavor):
     """
     base_dir: path from source root to directory containing this gyp file,
               by gyp semantics, all input paths are relative to this
@@ -114,6 +111,7 @@ class NinjaWriter:
     self.base_dir = base_dir
     self.build_dir = build_dir
     self.ninja = ninja_syntax.Writer(output_file)
+    self.flavor = flavor
 
     # Relative path from build output dir to base dir.
     self.build_to_base = os.path.join(InvertRelativePath(build_dir), base_dir)
@@ -422,18 +420,32 @@ class NinjaWriter:
       self.ninja.variable('cc', '$cc_host')
       self.ninja.variable('cxx', '$cxx_host')
 
+    if self.flavor == 'mac':
+      # TODO(jeremya/thakis): Extract these from XcodeSettings instead.
+      cflags = []
+      cflags_c = []
+      cflags_cc = []
+      cflags_objc = []
+      cflags_objcc = []
+    else:
+      cflags = config.get('cflags', [])
+      cflags_c = config.get('cflags_c', [])
+      cflags_cc = config.get('cflags_cc', [])
+
     self.WriteVariableList('defines',
         [QuoteShellArgument(ninja_syntax.escape('-D' + d))
          for d in config.get('defines', [])])
     self.WriteVariableList('includes',
                            ['-I' + self.GypPathToNinja(i)
                             for i in config.get('include_dirs', [])])
-    self.WriteVariableList('cflags', map(self.ExpandSpecial,
-                                         config.get('cflags', [])))
-    self.WriteVariableList('cflags_c', map(self.ExpandSpecial,
-                                           config.get('cflags_c', [])))
-    self.WriteVariableList('cflags_cc', map(self.ExpandSpecial,
-                                            config.get('cflags_cc', [])))
+    self.WriteVariableList('cflags', map(self.ExpandSpecial, cflags))
+    self.WriteVariableList('cflags_c', map(self.ExpandSpecial, cflags_c))
+    self.WriteVariableList('cflags_cc', map(self.ExpandSpecial, cflags_cc))
+    if self.flavor == 'mac':
+      self.WriteVariableList('cflags_objc', map(self.ExpandSpecial,
+                                             cflags_objc))
+      self.WriteVariableList('cflags_objcc', map(self.ExpandSpecial,
+                                              cflags_objcc))
     self.ninja.newline()
     outputs = []
     for source in sources:
@@ -443,6 +455,10 @@ class NinjaWriter:
         command = 'cxx'
       elif ext in ('c', 's', 'S'):
         command = 'cc'
+      elif self.flavor == 'mac' and ext == 'm':
+        command = 'objc'
+      elif self.flavor == 'mac' and ext == 'mm':
+        command = 'objcxx'
       else:
         # TODO: should we assert here on unexpected extensions?
         continue
@@ -498,9 +514,14 @@ class NinjaWriter:
     command = command_map[spec['type']]
 
     if output_uses_linker:
+      if self.flavor == 'mac':
+        # TODO(jeremya/thakis): Get this from XcodeSettings.
+        ldflags = []
+      else:
+        ldflags = config.get('ldflags', [])
       self.WriteVariableList('ldflags',
                              gyp.common.uniquer(map(self.ExpandSpecial,
-                                                    config.get('ldflags', []))))
+                                                    ldflags)))
       self.WriteVariableList('libs',
                              gyp.common.uniquer(map(self.ExpandSpecial,
                                                     spec.get('libraries', []))))
@@ -534,6 +555,10 @@ class NinjaWriter:
       'loadable_module': 'so',
       'shared_library': 'so',
       }
+    # TODO(thakis/jeremya): Remove once the mac path name computation is done
+    # by XcodeSettings.
+    if self.flavor == 'mac':
+      DEFAULT_EXTENSION['shared_library'] = 'dylib'
     extension = spec.get('product_extension',
                          DEFAULT_EXTENSION.get(spec['type'], ''))
     if extension:
@@ -576,6 +601,10 @@ class NinjaWriter:
       if self.toolset != 'target':
         libdir = 'lib/%s' % self.toolset
       return os.path.join(libdir, filename)
+    # TODO(thakis/jeremya): Remove once the mac path name computation is done
+    # by XcodeSettings.
+    elif spec['type'] == 'static_library' and self.flavor == 'mac':
+      return filename
     else:
       return self.GypPathToUniqueOutput(filename, qualified=False)
 
@@ -619,6 +648,32 @@ def CalculateVariables(default_variables, params):
   default_variables['LINKER_SUPPORTS_ICF'] = \
       gyp.system_test.TestLinkerSupportsICF(cc_command=cc_target)
 
+  flavor = gyp.common.GetFlavor(params)
+  if flavor == 'mac':
+    default_variables.setdefault('OS', 'mac')
+    default_variables.setdefault('SHARED_LIB_SUFFIX', '.dylib')
+
+    # TODO(jeremya/thakis): Set SHARED_LIB_DIR / LIB_DIR.
+
+    # Copy additional generator configuration data from Xcode, which is shared
+    # by the Mac Ninja generator.
+    import gyp.generator.xcode as xcode_generator
+    global generator_additional_non_configuration_keys
+    generator_additional_non_configuration_keys = getattr(xcode_generator,
+        'generator_additional_non_configuration_keys', [])
+    global generator_additional_path_sections
+    generator_additional_path_sections = getattr(xcode_generator,
+        'generator_additional_path_sections', [])
+    global generator_extra_sources_for_rules
+    generator_extra_sources_for_rules = getattr(xcode_generator,
+        'generator_extra_sources_for_rules', [])
+  else:
+    operating_system = flavor
+    if flavor == 'android':
+      operating_system = 'linux'  # Keep this legacy behavior for now.
+    default_variables.setdefault('OS', operating_system)
+    default_variables.setdefault('SHARED_LIB_SUFFIX', '.so')
+
 
 def OpenOutput(path):
   """Open |path| for writing, creating directories if necessary."""
@@ -631,6 +686,7 @@ def OpenOutput(path):
 
 def GenerateOutput(target_list, target_dicts, data, params):
   options = params['options']
+  flavor = gyp.common.GetFlavor(params)
   generator_flags = params.get('generator_flags', {})
 
   if options.generator_output:
@@ -653,7 +709,13 @@ def GenerateOutput(target_list, target_dicts, data, params):
   # TODO: compute cc/cxx/ld/etc. by command-line arguments and system tests.
   master_ninja.variable('cc', os.environ.get('CC', 'gcc'))
   master_ninja.variable('cxx', os.environ.get('CXX', 'g++'))
-  master_ninja.variable('ld', '$cxx -Wl,--threads -Wl,--thread-count=4')
+  # TODO(bradnelson): remove NOGOLD when this is resolved:
+  #     http://code.google.com/p/chromium/issues/detail?id=108251
+  if flavor != 'mac' and not os.environ.get('NOGOLD'):
+    master_ninja.variable('ld', '$cxx -Wl,--threads -Wl,--thread-count=4')
+  else:
+    # TODO(jeremya/thakis): flock
+    master_ninja.variable('ld', '$cxx')
   master_ninja.variable('cc_host', '$cc')
   master_ninja.variable('cxx_host', '$cxx')
   master_ninja.newline()
@@ -670,25 +732,60 @@ def GenerateOutput(target_list, target_dicts, data, params):
     command=('$cxx -MMD -MF $out.d $defines $includes $cflags $cflags_cc '
              '-c $in -o $out'),
     depfile='$out.d')
-  master_ninja.rule(
-    'alink',
-    description='AR $out',
-    command='rm -f $out && ar rcsT $out $in')
-  master_ninja.rule(
-    'solink',
-    description='SOLINK $out',
-    command=('$ld -shared $ldflags -o $out -Wl,-soname=$soname '
-             '-Wl,--whole-archive $in -Wl,--no-whole-archive $libs'))
-  master_ninja.rule(
-    'solink_module',
-    description='SOLINK(module) $out',
-    command=('$ld -shared $ldflags -o $out -Wl,-soname=$soname '
-             '-Wl,--start-group $in -Wl,--end-group $libs'))
-  master_ninja.rule(
-    'link',
-    description='LINK $out',
-    command=('$ld $ldflags -o $out -Wl,-rpath=\$$ORIGIN/lib '
-             '-Wl,--start-group $in -Wl,--end-group $libs'))
+  if flavor != 'mac':
+    master_ninja.rule(
+      'alink',
+      description='AR $out',
+      command='rm -f $out && ar rcsT $out $in')
+    master_ninja.rule(
+      'solink',
+      description='SOLINK $out',
+      command=('$ld -shared $ldflags -o $out -Wl,-soname=$soname '
+               '-Wl,--whole-archive $in -Wl,--no-whole-archive $libs'))
+    master_ninja.rule(
+      'solink_module',
+      description='SOLINK(module) $out',
+      command=('$ld -shared $ldflags -o $out -Wl,-soname=$soname '
+               '-Wl,--start-group $in -Wl,--end-group $libs'))
+    master_ninja.rule(
+      'link',
+      description='LINK $out',
+      command=('$ld $ldflags -o $out -Wl,-rpath=\$$ORIGIN/lib '
+               '-Wl,--start-group $in -Wl,--end-group $libs'))
+  else:
+    master_ninja.rule(
+      'objc',
+      description='OBJC $out',
+      command=('$cc -MMD -MF $out.d $defines $includes $cflags $cflags_c '
+               '$cflags_objc -c $in -o $out'),
+      depfile='$out.d')
+    master_ninja.rule(
+      'objcxx',
+      description='OBJCXX $out',
+      command=('$cxx -MMD -MF $out.d $defines $includes $cflags $cflags_cc '
+               '$cflags_objcc -c $in -o $out'),
+      depfile='$out.d')
+    master_ninja.rule(
+      'alink',
+      description='LIBTOOL-STATIC $out',
+      command='rm -f $out && libtool -static -o $out $in')
+    # TODO(thakis): The solink_module rule is likely wrong. Xcode seems to pass
+    # -bundle -single_module here (for osmesa.so).
+    master_ninja.rule(
+      'solink',
+      description='SOLINK $out',
+      command=('$ld -shared $ldflags -o $out '
+               '$in $libs'))
+    master_ninja.rule(
+      'solink_module',
+      description='SOLINK(module) $out',
+      command=('$ld -shared $ldflags -o $out '
+               '$in $libs'))
+    master_ninja.rule(
+      'link',
+      description='LINK $out',
+      command=('$ld $ldflags -o $out '
+               '$in $libs'))
   master_ninja.rule(
     'stamp',
     description='STAMP $out',
@@ -696,7 +793,7 @@ def GenerateOutput(target_list, target_dicts, data, params):
   master_ninja.rule(
     'copy',
     description='COPY $in $out',
-    command='ln -f $in $out 2>/dev/null || cp -af $in $out')
+    command='ln -f $in $out 2>/dev/null || (rm -rf $out && cp -af $in $out)')
   master_ninja.newline()
 
   all_targets = set()
@@ -726,7 +823,8 @@ def GenerateOutput(target_list, target_dicts, data, params):
     writer = NinjaWriter(target_outputs, base_path, builddir,
                          OpenOutput(os.path.join(options.toplevel_dir,
                                                  builddir,
-                                                 output_file)))
+                                                 output_file)),
+                         flavor)
     master_ninja.subninja(output_file)
 
     output, compile_depends = writer.WriteSpec(spec, config)
diff --git a/tools/gyp/pylib/gyp/input.py b/tools/gyp/pylib/gyp/input.py
index ef30efa4da..19a16288cd 100644
--- a/tools/gyp/pylib/gyp/input.py
+++ b/tools/gyp/pylib/gyp/input.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2011 The Chromium Authors. All rights reserved.
+# Copyright (c) 2011 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
@@ -1358,6 +1358,13 @@ class DependencyGraphNode(object):
       # True) and this target won't be linked.
       return dependencies
 
+    # Don't traverse 'none' targets if explicitly excluded.
+    if (target_type == 'none' and
+        not targets[self.ref].get('dependencies_traverse', True)):
+      if self.ref not in dependencies:
+        dependencies.append(self.ref)
+      return dependencies
+
     # Executables and loadable modules are already fully and finally linked.
     # Nothing else can be a link dependency of them, there can only be
     # dependencies in the sense that a dependent target might run an
diff --git a/tools/gyp/pylib/gyp/ninja_syntax.py b/tools/gyp/pylib/gyp/ninja_syntax.py
index d4776fb236..35cda05707 100644
--- a/tools/gyp/pylib/gyp/ninja_syntax.py
+++ b/tools/gyp/pylib/gyp/ninja_syntax.py
@@ -10,6 +10,10 @@ use Python.
 """
 
 import textwrap
+import re
+
+def escape_spaces(word):
+    return word.replace('$ ','$$ ').replace(' ','$ ')
 
 class Writer(object):
     def __init__(self, output, width=78):
@@ -24,29 +28,40 @@ class Writer(object):
             self.output.write('# ' + line + '\n')
 
     def variable(self, key, value, indent=0):
+        if value is None:
+            return
+        if isinstance(value, list):
+            value = ' '.join(value)
         self._line('%s = %s' % (key, value), indent)
 
-    def rule(self, name, command, description=None, depfile=None):
+    def rule(self, name, command, description=None, depfile=None,
+             generator=False):
         self._line('rule %s' % name)
         self.variable('command', command, indent=1)
         if description:
             self.variable('description', description, indent=1)
         if depfile:
             self.variable('depfile', depfile, indent=1)
+        if generator:
+            self.variable('generator', '1', indent=1)
 
     def build(self, outputs, rule, inputs=None, implicit=None, order_only=None,
               variables=None):
         outputs = self._as_list(outputs)
         all_inputs = self._as_list(inputs)[:]
+        out_outputs = map(escape_spaces, outputs)
+        all_inputs = map(escape_spaces, all_inputs)
 
         if implicit:
+            implicit = map(escape_spaces, self._as_list(implicit))
             all_inputs.append('|')
-            all_inputs.extend(self._as_list(implicit))
+            all_inputs.extend(implicit)
         if order_only:
+            order_only = map(escape_spaces, self._as_list(order_only))
             all_inputs.append('||')
-            all_inputs.extend(self._as_list(order_only))
+            all_inputs.extend(order_only)
 
-        self._line('build %s: %s %s' % (' '.join(outputs),
+        self._line('build %s: %s %s' % (' '.join(out_outputs),
                                         rule,
                                         ' '.join(all_inputs)))
 
@@ -62,28 +77,52 @@ class Writer(object):
     def subninja(self, path):
         self._line('subninja %s' % path)
 
+    def default(self, paths):
+        self._line('default %s' % ' '.join(self._as_list(paths)))
+
     def _line(self, text, indent=0):
         """Write 'text' word-wrapped at self.width characters."""
         leading_space = '  ' * indent
         while len(text) > self.width:
             # The text is too wide; wrap if possible.
 
-            # Find the rightmost space that would obey our width constraint.
-            available_space = self.width - len(leading_space) - len(' $')
-            space = text.rfind(' ', 0, available_space)
-            if space < 0:
-                # No such space; just use the first space we can find.
-                space = text.find(' ', available_space)
-            if space < 0:
-                # Give up on breaking.
-                break
+            self.output.write(leading_space)
 
-            self.output.write(leading_space + text[0:space] + ' $\n')
-            text = text[space+1:]
+            available_space = self.width - len(leading_space) - len(' $')
+
+            # Write as much as we can into this line.
+            done = False
+            written_stuff = False
+            while available_space > 0:
+                space = re.search('((\$\$)+([^$]|^)|[^$]|^) ', text)
+                if space:
+                    space_idx = space.start() + 1
+                else:
+                    # No spaces left.
+                    done = True
+                    break
+
+                if space_idx > available_space:
+                    # We're out of space.
+                    if written_stuff:
+                        # See if we can fit it on the next line.
+                        break
+                    # If we haven't written anything yet on this line, don't
+                    # try to wrap.
+                self.output.write(text[0:space_idx] + ' ')
+                written_stuff = True
+                text = text[space_idx+1:]
+                available_space -= space_idx+1
+
+            self.output.write('$\n')
 
             # Subsequent lines are continuations, so indent them.
             leading_space = '  ' * (indent+2)
 
+            if done:
+                # No more spaces, so bail.
+                break
+
         self.output.write(leading_space + text + '\n')
 
     def _as_list(self, input):
diff --git a/tools/gyp/test/dependencies/b/b.gyp b/tools/gyp/test/dependencies/b/b.gyp
index f09e1ff13c..893dc64d65 100755
--- a/tools/gyp/test/dependencies/b/b.gyp
+++ b/tools/gyp/test/dependencies/b/b.gyp
@@ -11,5 +11,12 @@
         'b.c',
       ],
     },
+    {
+      'target_name': 'b3',
+      'type': 'static_library',
+      'sources': [
+        'b3.c',
+      ],
+    },
   ],
 }
diff --git a/tools/gyp/test/dependencies/b/b3.c b/tools/gyp/test/dependencies/b/b3.c
new file mode 100755
index 0000000000..287f67ff31
--- /dev/null
+++ b/tools/gyp/test/dependencies/b/b3.c
@@ -0,0 +1,9 @@
+/*
+ * Copyright (c) 2011 Google Inc. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+int funcB() {
+  return 3;
+}
diff --git a/tools/gyp/test/dependencies/gyptest-lib-only.py b/tools/gyp/test/dependencies/gyptest-lib-only.py
index 4355d578ae..02159f5f15 100755
--- a/tools/gyp/test/dependencies/gyptest-lib-only.py
+++ b/tools/gyp/test/dependencies/gyptest-lib-only.py
@@ -29,7 +29,7 @@ if sys.platform == 'darwin':
   if test.format == 'xcode':
     test.built_file_must_not_exist('b', type=test.STATIC_LIB)
   else:
-    assert test.format == 'make'
+    assert test.format in ('make', 'ninja')
     test.built_file_must_exist('b', type=test.STATIC_LIB)
 else:
   # Make puts the resulting library in a directory matching the input gyp file;
diff --git a/tools/gyp/test/dependencies/gyptest-none-traversal.py b/tools/gyp/test/dependencies/gyptest-none-traversal.py
new file mode 100755
index 0000000000..c09063dad3
--- /dev/null
+++ b/tools/gyp/test/dependencies/gyptest-none-traversal.py
@@ -0,0 +1,25 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2011 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Verify that static library dependencies don't traverse none targets, unless
+explicitly specified.
+"""
+
+import TestGyp
+
+import sys
+
+test = TestGyp.TestGyp()
+
+test.run_gyp('none_traversal.gyp')
+
+test.build('none_traversal.gyp', test.ALL)
+
+test.run_built_executable('needs_chain', stdout="2\n")
+test.run_built_executable('doesnt_need_chain', stdout="3\n")
+
+test.pass_test()
diff --git a/tools/gyp/test/dependencies/main.c b/tools/gyp/test/dependencies/main.c
new file mode 100644
index 0000000000..185bd482f2
--- /dev/null
+++ b/tools/gyp/test/dependencies/main.c
@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2011 Google Inc. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <stdio.h>
+
+extern int funcA();
+
+int main() {
+  printf("%d\n", funcA());
+  return 0;
+}
diff --git a/tools/gyp/test/dependencies/none_traversal.gyp b/tools/gyp/test/dependencies/none_traversal.gyp
new file mode 100755
index 0000000000..3d8ab30aff
--- /dev/null
+++ b/tools/gyp/test/dependencies/none_traversal.gyp
@@ -0,0 +1,46 @@
+# Copyright (c) 2009 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'targets': [
+    {
+      'target_name': 'needs_chain',
+      'type': 'executable',
+      'sources': [
+        'a.c',
+        'main.c',
+      ],
+      'dependencies': ['chain'],
+    },
+    {
+      'target_name': 'chain',
+      'type': 'none',
+      'dependencies': ['b/b.gyp:b'],
+    },
+    {
+      'target_name': 'doesnt_need_chain',
+      'type': 'executable',
+      'sources': [
+        'main.c',
+      ],
+      'dependencies': ['no_chain', 'other_chain'],
+    },
+    {
+      'target_name': 'no_chain',
+      'type': 'none',
+      'sources': [
+      ],
+      'dependencies': ['b/b.gyp:b'],
+      'dependencies_traverse': 0,
+    },
+    {
+      'target_name': 'other_chain',
+      'type': 'static_library',
+      'sources': [
+        'a.c',
+      ],
+      'dependencies': ['b/b.gyp:b3'],
+    },
+  ],
+}
diff --git a/tools/gyp/test/lib/TestGyp.py b/tools/gyp/test/lib/TestGyp.py
index a65c3e2440..2b4b0db967 100644
--- a/tools/gyp/test/lib/TestGyp.py
+++ b/tools/gyp/test/lib/TestGyp.py
@@ -449,6 +449,11 @@ class TestGypNinja(TestGypBase):
   def run_built_executable(self, name, *args, **kw):
     # Enclosing the name in a list avoids prepending the original dir.
     program = [self.built_file_path(name, type=self.EXECUTABLE, **kw)]
+    if sys.platform == 'darwin':
+      libdir = os.path.join('out', 'Default', 'lib')
+      if self.configuration:
+        libdir = os.path.join('out', self.configuration, 'lib')
+      os.environ['DYLD_LIBRARY_PATH'] = libdir
     return self.run(program=program, *args, **kw)
 
   def built_file_path(self, name, type=None, **kw):
@@ -458,9 +463,10 @@ class TestGypNinja(TestGypBase):
       result.append(chdir)
     result.append('out')
     result.append(self.configuration_dirname())
-    if type in (self.STATIC_LIB,):
-      result.append('obj')
-    elif type in (self.SHARED_LIB,):
+    if type == self.STATIC_LIB:
+      if sys.platform != 'darwin':
+        result.append('obj')
+    elif type == self.SHARED_LIB:
       result.append('lib')
     subdir = kw.get('subdir')
     if subdir:
@@ -469,8 +475,13 @@ class TestGypNinja(TestGypBase):
     return self.workpath(*result)
 
   def up_to_date(self, gyp_file, target=None, **kw):
-    kw['stdout'] = "ninja: no work to do.\n"
-    return self.build(gyp_file, target, **kw)
+    result = self.build(gyp_file, target, **kw)
+    if not result:
+      stdout = self.stdout()
+      if 'ninja: no work to do' not in stdout:
+        self.report_not_up_to_date()
+        self.fail_test()
+    return result
 
 
 class TestGypMSVS(TestGypBase):
@@ -569,7 +580,7 @@ class TestGypMSVS(TestGypBase):
     'C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO 10.0\VC\BIN\1033\CLUI.DLL'
     was modified at 02/21/2011 17:03:30, which is newer than '' which was
     modified at 01/01/0001 00:00:00.
-    
+
     The workaround is to specify a workdir when instantiating the test, e.g.
     test = TestGyp.TestGyp(workdir='workarea')
     """