Use -O2 instead -O3 for Android build.

build/android.gypi

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 57 matching lines @@
     'android_webview_build%': '<(android_webview_build)',
     'OS': 'android',
   },  # variables
   'target_defaults': {
     'defines': [
       'ANDROID',
       'V8_ANDROID_LOG_STDOUT',
     ],
     'configurations': {
       'Release': {
-        'cflags!': [
-          '-O2',
-          '-Os',
-        ],
         'cflags': [
-          '-fdata-sections',
-          '-ffunction-sections',
           '-fomit-frame-pointer',
-          '-O3',
         ],
       },  # Release
     },  # configurations
     'cflags': [ '-Wno-abi', '-Wall', '-W', '-Wno-unused-parameter',
                 '-Wnon-virtual-dtor', '-fno-rtti', '-fno-exceptions', ],
     'target_conditions': [
       ['_toolset=="target"', {
         'cflags!': [
           '-pthread',  # Not supported by Android toolchain.
         ],
@@ skipping 153 matching lines @@
         'ldflags!': [
           '-Wl,-z,noexecstack',
           '-Wl,--gc-sections',
           '-Wl,-O1',
           '-Wl,--as-needed',
         ],
       }],
     ],  # target_conditions
   },  # target_defaults
 }