Android: bake GCC flags for perf into profiling=1 in GYP_DEFINES

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 23ea72721deacaf04a837ab34ffd401e8be2e224..e22279986604ab08881e84342a5ff85a686a3123 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -3447,8 +3447,14 @@
                       }],
                       ['profiling==1', {
                         'cflags': [
-                          '-marm', # Probably reduntant, but recommend by "perf" docs.
-                          '-mapcs-frame', # Seems required by -fno-omit-frame-pointer.
+                          # Thumb code with frame pointer makes chrome crash
+                          # early.
+                          '-marm',
+                          '-mapcs-frame', # Required by -fno-omit-frame-pointer.
+                          '-fno-optimize-sibling-calls',

[Sami, 2014/05/15 13:34:32]

Looks like this one is also set by profiling_full_stack_frames=1. What's the
advantage of having it here too?

[pasko, 2014/05/15 14:34:53]

I noticed too. The profiling=1 is supposed to be the default way to use perf.
Without -fno-optimize-sibling-calls I found perf reports on Android to be often
misleading. On the other hand, profiling_full_stack_frames=1 disallows inlining
(sort of), which I never needed, so not enabling it to be closer to profiling=0
performance.

profiling=1 *and* profiling_full_stack_frames=1 together may be useful in some
cases (such as for memory profiling?), so let's have the two modes.

+                        ],
+                        'cflags!': [
+                          '-fomit-frame-pointer',

[Sami, 2014/05/15 13:34:32]

BTW, is this just a safe guard or did we end up removing frame pointers in some
cases?

[pasko, 2014/05/15 14:34:53]

We add the -fomit-frame-pointer flag on Android at line 3184 in this file.

                         ],
                       }],
                       ['clang==1', {