Use bundled gold by default when building for Android.

The bundled gold contains a number of bug fixes (mostly LTO-related, but also
http://crbug.com/161942), so use it instead of the NDK gold. Both versions
of gold are based on the same version of binutils (2.24), so this should be
relatively safe.

BUG=161942,469376
R=thakis@chromium.org
TEST=Built libchromeshell.so with default GYP_DEFINES with and without this change, verified that binaries are equivalent

Review URL: https://codereview.chromium.org/1084133002

Cr-Commit-Position: refs/heads/master@{#325334}

build/common.gypi

@@ -861,7 +861,7 @@
         # are using a custom toolchain and need to control -B in ldflags.
         # Do not use 32-bit gold on 32-bit hosts as it runs out address space
         # for component=static_library builds.
-        ['OS=="linux" and (target_arch=="x64" or target_arch=="arm")', {
+        ['(OS=="linux" or OS=="android") and (target_arch=="x64" or target_arch=="arm")', {
           'linux_use_bundled_gold%': 1,
         }, {
           'linux_use_bundled_gold%': 0,
@@ -3994,6 +3994,8 @@
                           '-no-integrated-as',
                           '-B<(android_toolchain)',  # Else /usr/bin/as gets picked up.
                         ],
+                      }],
+                      ['clang==1 and linux_use_bundled_gold==0', {
                         'ldflags': [
                           # Let clang find the ld.gold in the NDK.
                           '--gcc-toolchain=<(android_toolchain)/..',