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

tools/gyp/configurations_android.gypi

Index: tools/gyp/configurations_android.gypi
diff --git a/tools/gyp/configurations_android.gypi b/tools/gyp/configurations_android.gypi
index 9a0c96d0c8a732fccedf6688d467f937d8fdb364..cadd1224d68a6bfd930e0db2652b5760923b2b36 100644
--- a/tools/gyp/configurations_android.gypi
+++ b/tools/gyp/configurations_android.gypi
@@ -55,6 +55,16 @@
         'defines': [
           'DEBUG',
         ],
+        'conditions': [
+          ['c_frame_pointers==1', {
+            'cflags': [
+              '-fno-omit-frame-pointer',
+            ],
+            'defines': [
+              'PROFILE_NATIVE_CODE'
+            ],
+          }],
+        ],
       },
       'Dart_Android_Release': {
         'abstract': 1,
@@ -68,11 +78,18 @@
         '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,