Change Android toolchain to GCC 4.9.

build/config/android/config.gni

 # Copyright 2014 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.
 
 # This file contains common system config stuff for the Android build.
 
 if (is_android) {
   declare_args() {
     # Absolute directory containing the Android source code.
     android_src = ""
@@ skipping 60 matching lines @@
 
   # Subdirectories inside android_ndk_root that contain the sysroot for the
   # associated platform.
   _android_api_level = 14
   x86_android_sysroot_subdir = "platforms/android-${_android_api_level}/arch-x86"
   arm_android_sysroot_subdir = "platforms/android-${_android_api_level}/arch-arm"
   mips_android_sysroot_subdir = "platforms/android-${_android_api_level}/arch-mips"
 
   # Toolchain root directory for each build. The actual binaries are inside
   # a "bin" directory inside of these.
-  _android_toolchain_version = "4.8"
+  _android_toolchain_version = "4.9"
   x86_android_toolchain_root = "$android_ndk_root/toolchains/x86-${_android_toolchain_version}/prebuilt/${android_host_os}-${android_host_arch}"
   arm_android_toolchain_root = "$android_ndk_root/toolchains/arm-linux-androideabi-${_android_toolchain_version}/prebuilt/${android_host_os}-${android_host_arch}"
   mips_android_toolchain_root = "$android_ndk_root/toolchains/mipsel-linux-android-${_android_toolchain_version}/prebuilt/${android_host_os}-${android_host_arch}"
 
   # Location of libgcc. This is only needed for the current GN toolchain, so we
   # only need to define the current one, rather than one for every platform
   # like the toolchain roots.
   if (cpu_arch == "x86") {
     android_prebuilt_arch = "android-x86"
     _binary_prefix = "i686-linux-android"
@@ skipping 46 matching lines @@
     android_app_abi = "mips"
   } else {
     assert(false, "Unknown Android ABI: " + cpu_arch)
   }
 } else {
   if (!defined(is_android_webview_build)) {
     is_android_webview_build = false
   }
   use_system_stlport = false
 }