Generate Android .isolate files used for test()s

Tests use write_runtime_deps to have GN write out all runtime_deps, then
use a new script "generate_isolate.py" to filter the files and create a
.isolate.

TBR=vollick
BUG=589318
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1904823003

Cr-Original-Commit-Position: refs/heads/master@{#389105}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 964da0f3923afb10a52dfe81484d7f3dcb18bad6

android/pylib/gtest/gtest_test_instance.py

@@ -12,6 +12,7 @@ from pylib import constants
 from pylib.constants import host_paths
 from pylib.base import base_test_result
 from pylib.base import test_instance
+from pylib.utils import isolator
 
 with host_paths.SysPath(host_paths.BUILD_COMMON_PATH):
   import unittest_util # pylint: disable=import-error
@@ -196,7 +197,8 @@ class GtestTestInstance(test_instance.TestInstance):
         args.isolate_file_path = os.path.join(
             host_paths.DIR_SOURCE_ROOT, default_isolate_file_path)
 
-    if args.isolate_file_path:
+    if (args.isolate_file_path and
+        not isolator.IsIsolateEmpty(args.isolate_file_path)):
       self._isolate_abs_path = os.path.abspath(args.isolate_file_path)
       self._isolate_delegate = isolate_delegate
       self._isolated_abs_path = os.path.join(

android/pylib/instrumentation/instrumentation_test_instance.py

@@ -17,6 +17,7 @@ from pylib.base import test_instance
 from pylib.constants import host_paths
 from pylib.instrumentation import test_result
 from pylib.instrumentation import instrumentation_parser
+from pylib.utils import isolator
 from pylib.utils import proguard
 
 with host_paths.SysPath(host_paths.BUILD_COMMON_PATH):
@@ -292,7 +293,8 @@ class InstrumentationTestInstance(test_instance.TestInstance):
 
   def _initializeDataDependencyAttributes(self, args, isolate_delegate):
     self._data_deps = []
-    if args.isolate_file_path:
+    if (args.isolate_file_path and
+        not isolator.IsIsolateEmpty(args.isolate_file_path)):
       if os.path.isabs(args.isolate_file_path):
         self._isolate_abs_path = args.isolate_file_path
       else:

android/pylib/utils/isolator.py

@@ -54,6 +54,12 @@ def DefaultConfigVariables():
   }
 
 
+def IsIsolateEmpty(isolate_path):
+  """Returns whether there are no files in the .isolate."""
+  with open(isolate_path) as f:
+    return "'files': []" in f.read()
+
+
 class Isolator(object):
   """Manages calls to isolate.py for the android test runner scripts."""
 

config/android/internal_rules.gni

@@ -2095,6 +2095,7 @@ template("test_runner_script") {
     depfile = "$target_gen_dir/$target_name.d"
 
     data_deps += [ "//build/android:test_runner_py" ]
+    data = []
 
     test_runner_args = [
       _test_type,
@@ -2179,6 +2180,7 @@ template("test_runner_script") {
       }
     }
     if (defined(invoker.isolate_file)) {
+      data += [ invoker.isolate_file ]
       test_runner_args += [
         "--isolate-file-path",
         rebase_path(invoker.isolate_file, root_build_dir),
@@ -2209,9 +2211,7 @@ template("test_runner_script") {
       depfile,
       generated_script,
     ]
-    data = [
-      generated_script,
-    ]
+    data += [ generated_script ]
 
     args = [
       "--depfile",