Changed android toolchain to use GCC 4.8

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/gcc/gcc_version.gni")
 import("//build/config/android/config.gni")
 if (cpu_arch == "arm") {
   import("//build/config/arm.gni")
 }
 
 declare_args() {
   # Normally, Android builds are lightly optimized, even for debug builds, to
   # keep binary size down. Setting this flag to true disables such optimization
   android_full_debug = false
 }
@@ skipping 194 matching lines @@
 
   # Android-specific flags setup.
   # -----------------------------
   if (is_android) {
     cflags += [
       "-ffunction-sections",
       "-funwind-tables",
       "-fno-short-enums",
     ]
     if (!is_clang) {
-      # Clang doesn't support this one.
-      cflags += [ "-finline-limit=64" ]
+      # Clang doesn't support these flags.
+      cflags += [
+        "-finline-limit=64",
+        # The following 6 options are disabled to save on
+        # binary size in gcc 4.8.
+        # TODO(fdegans) Reevaluate when we upgrade GCC.
+        "-fno-partial-inlining",
+        "-fno-early-inlining",
+        "-fno-tree-copy-prop",
+        "-fno-tree-loop-optimize",
+        "-fno-move-loop-invariants",
+        "-fno-caller-saves",
+      ]
     }
     if (is_android_webview_build) {
       # Android predefines this as 1; undefine it here so Chromium can redefine
       # it later to be 2 for chromium code and unset for third party code. This
       # works because cflags are added before defines.
       # TODO(brettw) the above comment seems incorrect. We specify defines
       # before cflags on our compiler command lines.
       cflags += [ "-U_FORTIFY_SOURCE" ]
     }
 
@@ skipping 371 matching lines @@
         # Disabling c++0x-compat should be handled in WebKit, but
         # this currently doesn't work because gcc_version is not set
         # correctly when building with the Android build system.
         # TODO(torne): Fix this in WebKit.
         "-Wno-error=c++0x-compat",
         # Other things unrelated to -Wextra:
         "-Wno-non-virtual-dtor",
         "-Wno-sign-promo",
       ]
     }
+
+    if (gcc_version >= 48) {
+      # Don't warn about the "typedef 'foo' locally defined but not used"
+      # for gcc 4.8.
+      # TODO: remove this flag once all builds work. See crbug.com/227506
+      cflags += [
+        "-Wno-unused-local-typedefs",
+      ]
+    }
   }
 }
 
 # This will generate warnings when using Clang if code generates exit-time
 # destructors, which will slow down closing the program.
 # TODO(thakis): Make this a blacklist instead, http://crbug.com/101600
 config("wexit_time_destructors") {
   if (is_clang) {
     cflags = [ "-Wexit-time-destructors" ]
   }
@@ skipping 122 matching lines @@
   } else {
     cflags = [ "-g1" ]
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }
-