Add build configuration variable 'c_frame_pointers' to control whether or not frame pointers are in…

tools/gyp/configurations_android.gypi

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # Definitions for building standalone Dart binaries to run on Android.
 # This is mostly excerpted from:
 # http://src.chromium.org/viewvc/chrome/trunk/src/build/common.gypi
 
 {
   'variables': {
@@ skipping 37 matching lines @@
           ['_toolset=="host"', {
             'cflags': [ '-m32', '-pthread' ],
           }],
         ],
       },
       'Dart_Android_Debug': {
         'abstract': 1,
         'defines': [
           'DEBUG',
         ],
+        'conditions': [
+          ['c_frame_pointers==1', {
+            'cflags': [
+              '-fno-omit-frame-pointer',
+            ],
+            'defines': [
+              'PROFILE_NATIVE_CODE'
+            ],
+          }],
+        ],
       },
       'Dart_Android_Release': {
         'abstract': 1,
         'defines': [
           'NDEBUG',
         ],
         'cflags!': [
           '-O2',
           '-Os',
         ],
         'cflags': [
           '-fdata-sections',
           '-ffunction-sections',
-          # Uncomment the following line and pass --profile-vm to enable
-          # profiling of C++ code within Observatory.
-          # '-fno-omit-frame-pointer',
           '-O3',
         ],
+        'conditions': [
+          ['c_frame_pointers==1', {
+            'cflags': [
+              '-fno-omit-frame-pointer',
+            ],
+            'defines': [
+              'PROFILE_NATIVE_CODE'
+            ],
+          }],
+        ],
       },
       'Dart_Android_ia32_Base': {
         'abstract': 1,
         'variables': {
           'android_sysroot': '<(android_ndk_root)/platforms/android-14/arch-x86',
           'android_ndk_include': '<(android_sysroot)/usr/include',
           'android_ndk_lib': '<(android_sysroot)/usr/lib',
         },
         'target_conditions': [
           ['_toolset=="target"', {
@@ skipping 99 matching lines @@
             ],
           }],
           ['_toolset=="host"', {
             'ldflags': [ '-m32', '-pthread' ],
           }],
         ],
       },
     },  # configurations
   },  # target_defaults
 }