mac: Hook up allocator shim during app startup.

content/app/content_main_runner.cc

Index: content/app/content_main_runner.cc
diff --git a/content/app/content_main_runner.cc b/content/app/content_main_runner.cc
index ee6ab17a0dc24ac400302dd074a0b2cdae168332..181ba0e2b7260b6c1fc5394ba364226ccbee049e 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -15,6 +15,7 @@
 
 #include "base/allocator/allocator_check.h"
 #include "base/allocator/allocator_extension.h"
+#include "base/allocator/features.h"
 #include "base/at_exit.h"
 #include "base/base_switches.h"
 #include "base/command_line.h"
@@ -86,6 +87,7 @@
 #include "ui/base/win/atl_module.h"
 #include "ui/display/win/dpi.h"
 #elif defined(OS_MACOSX)
+#include "base/allocator/allocator_shim.h"

[Primiano Tucci (use gerrit), 2017/02/06 10:19:10]

I never if you can rely on the transitive dependency on the buildflag target
(content -> base -> base/allocator:features) or you need a direct dependency
from content -> allocator:features.
Can you check that if you do:
ninja -C out/whatever object/content/app/content_main_runner.o (or whatever is
the right path)
rm out/whatever/gen/base/allocator/features.h
ninja -C out/whatever object/content/app/content_main_runner.o 

everything works?

[erikchen, 2017/02/06 21:22:18]

Done.

 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/power_monitor/power_monitor_device_source.h"
 #include "content/app/mac/mac_init.h"
@@ -475,6 +477,9 @@ class ContentMainRunnerImpl : public ContentMainRunner {
     env_mode_ = params.env_mode;
 #endif
 
+#if defined(OS_MACOSX) && BUILDFLAG(USE_EXPERIMENTAL_ALLOCATOR_SHIM)
+    base::allocator::InitializeAllocatorShim();
+#endif
     base::EnableTerminationOnOutOfMemory();

[Primiano Tucci (use gerrit), 2017/02/06 10:19:10]

I think you need to update EnableTerminationOnOutOfMemory in memory_mac.mm and
do:

#if BUILDFLAG(USE_EXPERIMENTAL_ALLOCATOR_SHIM)
  allocator::SetCallNewHandlerOnMallocFailure(true);
#endif

similarly to what happens in memory_linux.cc

Otherwise I think that when you enable the shim you will lose the suicide-on-oom
for the default malloc zone.
I'd expect this to make the OutOfMemoryDeathTest in memory_unittest.cc fail
(alright, the build flag is not enabled by default right now, that's why you
won't see this unless you run manually base_unittest).
If you run base_unittests do you see the failure?
If yes: it's all great, fix EnableTerminationOnOOM
If no:
 Option A: I am misunderstanding something
 Option B: the OutOfMemoryDeathTest are broken on mac and we should figure out
why

[erikchen, 2017/02/06 21:22:18]

Tests were passing because we weren't initializing the allocator shim in tests.
I've added the requisite plumbing and locally, tests pass with both
_default_use_experimental_allocator_shim=true and
_default_use_experimental_allocator_shim=false

 #if defined(OS_WIN)
     base::win::RegisterInvalidParamHandler();