Reland of [tracing] Add native allocation tracing mode.

base/base.gyp

Index: base/base.gyp
diff --git a/base/base.gyp b/base/base.gyp
index d627511d46a3bf877fe568e4df4dcfdaf50185cc..0dd106a348d53e0e4744840cb9fac336dbd3d1b3 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -13,6 +13,7 @@
   'targets': [
     {
       'target_name': 'base',
+      'hard_dependency': 1,

[Primiano Tucci (use gerrit), 2016/04/26 15:20:14]

Hmm this is a strong hammer. Not sure we needed, neither not sure it will fly.

I think I know what's going on.
You are depending on BUILDFLAG(ENABLE_PROFILING) in
heap_profiler_allocation_context_tracker.h.
heap_profiler_allocation_context_tracker.h is a header, and can get included in
arbitrary targets before base's dependency (and in particular
base_debugging_flags which generates the header) are generated.
Here's my proposal: you don't really need that ENABLE_PROFILING everywhere, I
think you can be a bit less aggressive in ifdefing code out, as follows:

1) drop the #if ENABLE_NATIVE_ALLOCATION_TRACES in
heap_profiler_allocation_context_tracker.h, doesn't add a lot of value hiding an
enum value behind that flag.
2) drop the ifdef from heap_profiler_allocation_context_tracker.cc,
make the call to debug::TraceStackFramePointers depend on
HAVE_TRACE_STACK_FRAME_POINTERS and, DCHECK/NOTREACHED if you hit that case
without HAVE_TRACE_STACK_FRAME_POINTERS being defined.
3) The only place left where you need the buildflag is memory_dump_manager.cc.
Move all that ifdef logic inside the memory_dump_manager.cc file. 

Ta-daa, this will just work because memory_dump_manager.cc is a translation unit
which builds only inside of base, and base has a dependency on the buildflag
header. 

       'type': '<(component)',
       'toolsets': ['host', 'target'],
       'variables': {