diff --git a/config/linux/pkg-config.py b/config/linux/pkg-config.py
index c1c0dc4f5..70cb5e961 100644
--- a/config/linux/pkg-config.py
+++ b/config/linux/pkg-config.py
@@ -12,8 +12,8 @@ from optparse import OptionParser
 # This script runs pkg-config, optionally filtering out some results, and
 # returns the result.
 #
-# The result will be [ <includes>, <cflags>, <libs>, <lib_dirs> ] where each
-# member is itself a list of strings.
+# The result will be [ <includes>, <cflags>, <libs>, <lib_dirs>, <ldflags> ]
+# where each member is itself a list of strings.
 #
 # You can filter out matches using "-v <regexp>" where all results from
 # pkgconfig matching the given regular expression will be ignored. You can
@@ -138,6 +138,7 @@ includes = []
 cflags = []
 libs = []
 lib_dirs = []
+ldflags = []
 
 for flag in all_flags[:]:
   if len(flag) == 0 or MatchesAnyRegexp(flag, strip_out):
@@ -145,14 +146,21 @@ for flag in all_flags[:]:
 
   if flag[:2] == '-l':
     libs.append(RewritePath(flag[2:], prefix, sysroot))
-  if flag[:2] == '-L':
+  elif flag[:2] == '-L':
     lib_dirs.append(RewritePath(flag[2:], prefix, sysroot))
   elif flag[:2] == '-I':
     includes.append(RewritePath(flag[2:], prefix, sysroot))
+  elif flag[:3] == '-Wl':
+    ldflags.append(flag)
+  elif flag == '-pthread':
+    # Many libs specify "-pthread" which we don't need since we always include
+    # this anyway. Removing it here prevents a bunch of duplicate inclusions on
+    # the command line.
+    pass
   else:
     cflags.append(flag)
 
 # Output a GN array, the first one is the cflags, the second are the libs. The
 # JSON formatter prints GN compatible lists when everything is a list of
 # strings.
-print json.dumps([includes, cflags, libs, lib_dirs])
+print json.dumps([includes, cflags, libs, lib_dirs, ldflags])
diff --git a/config/linux/pkg_config.gni b/config/linux/pkg_config.gni
index dd592236a..fdd31ba84 100644
--- a/config/linux/pkg_config.gni
+++ b/config/linux/pkg_config.gni
@@ -34,5 +34,6 @@ template("pkg_config") {
     cflags = pkgresult[1]
     libs = pkgresult[2]
     lib_dirs = pkgresult[3]
+    ldflags = pkgresult[4]
   }
 }
diff --git a/toolchain/linux/BUILD.gn b/toolchain/linux/BUILD.gn
index 74d287fec..38f4b184c 100644
--- a/toolchain/linux/BUILD.gn
+++ b/toolchain/linux/BUILD.gn
@@ -2,10 +2,10 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("../clang.gni")
-import("../goma.gni")
-import("../gcc_toolchain.gni")
 import("//build/config/sysroot.gni")
+import("//build/toolchain/clang.gni")
+import("//build/toolchain/gcc_toolchain.gni")
+import("//build/toolchain/goma.gni")
 
 if (is_gyp) {
   # Set the compilers for GYP to use. This logic is only relevant to GYP where
@@ -47,8 +47,6 @@ if (is_gyp) {
   }
 }
 
-# ARM --------------------------------------------------------------------------
-
 gcc_toolchain("arm") {
   cc = "arm-linux-gnueabi-gcc"
   cxx = "arm-linux-gnueabi-g++"
@@ -59,11 +57,22 @@ gcc_toolchain("arm") {
   toolchain_os = "linux"
 }
 
-# 32-bit -----------------------------------------------------------------------
-
 gcc_toolchain("x86") {
-  cc = "gcc"
-  cxx = "g++"
+  if (is_clang) {
+    if (use_clang_type_profiler) {
+      prefix = rebase_path("//third_party/llvm-allocated-type/Linux_ia32/bin",
+                           ".", root_build_dir)
+    } else {
+      prefix = rebase_path("//third_party/llvm-build/Release+Asserts/bin",
+                           ".", root_build_dir)
+    }
+    cc = "$prefix/clang"
+    cxx = "$prefix/clang++"
+  } else {
+    cc = "gcc"
+    cxx = "g++"
+  }
+
   ar = "ar"
   ld = cxx
 
@@ -72,8 +81,21 @@ gcc_toolchain("x86") {
 }
 
 gcc_toolchain("x64") {
-  cc = "gcc"
-  cxx = "g++"
+  if (is_clang) {
+    if (use_clang_type_profiler) {
+      prefix = rebase_path("//third_party/llvm-allocated-type/Linux_x64/bin",
+                           ".", root_build_dir)
+    } else {
+      prefix = rebase_path("//third_party/llvm-build/Release+Asserts/bin",
+                           ".", root_build_dir)
+    }
+    cc = "$prefix/clang"
+    cxx = "$prefix/clang++"
+  } else {
+    cc = "gcc"
+    cxx = "g++"
+  }
+
   ar = "ar"
   ld = cxx
 
@@ -81,8 +103,6 @@ gcc_toolchain("x64") {
   toolchain_os = "linux"
 }
 
-# MIPS -----------------------------------------------------------------------
-
 gcc_toolchain("mipsel") {
   cc = "mipsel-linux-gnu-gcc"
   cxx = "mipsel-linux-gnu-g++"