Hook up allocator shim on mac.

base/allocator/allocator_shim_override_cpp_symbols.h

Index: base/allocator/allocator_shim_override_cpp_symbols.h
diff --git a/base/allocator/allocator_shim_override_cpp_symbols.h b/base/allocator/allocator_shim_override_cpp_symbols.h
index 616716fb96f0dda2bc94d18ab18616c5e9acc3f3..8fc15c697a9d932066a64b9b0881fb19f21043ac 100644
--- a/base/allocator/allocator_shim_override_cpp_symbols.h
+++ b/base/allocator/allocator_shim_override_cpp_symbols.h
@@ -14,6 +14,46 @@
 
 #include "base/allocator/allocator_shim_internals.h"
 
+#if defined(OS_MACOSX)

[Primiano Tucci (use gerrit), 2017/01/28 05:10:02]

just checking: do we actually need these?
IIRC the reason why I had to introduce them was because the stdlibc++ on linux
was directly going to __libc_malloc, so was bypassing the malloc-shim.
For instance, on Windows we don't need to override the C++ symbols because they
under the hood end up through malloc.
I have no idea about the current situation on Mac OS. My only question is: what
do we do today for the suicide-on-OOM feature? IIRC on Mac today we don't
override the c++ symbols.
Essentially what I am saying here is:
- either the current suicide-on-oom logic is bugged, and we don't suicide on
"new" failure
OR
- this is unnecessary and you can just piggy back on the #if !defined(OS_WIN) of
allocator_shim.cc:246

[erikchen, 2017/01/31 02:21:22]

We don't, the implementation of libc++.dylib forwards to default malloc zone.

+
+SHIM_ALWAYS_EXPORT void* operator new(size_t size) {
+  return ShimCppNew(size);
+}
+
+SHIM_ALWAYS_EXPORT void operator delete(void* ptr)__THROW {
+  return ShimCppDelete(ptr);
+}
+
+SHIM_ALWAYS_EXPORT void* operator new[](size_t size) {
+  return ShimCppNew(size);
+}
+
+SHIM_ALWAYS_EXPORT void operator delete[](void* ptr) __THROW {
+  return ShimCppDelete(ptr);
+}
+
+SHIM_ALWAYS_EXPORT void* operator new(size_t size,
+                                      const std::nothrow_t&) __THROW {
+  return ShimCppNew(size);
+}
+
+SHIM_ALWAYS_EXPORT void* operator new[](size_t size,
+                                        const std::nothrow_t&) __THROW {
+  return ShimCppNew(size);
+}
+
+SHIM_ALWAYS_EXPORT void operator delete(void* ptr,
+                                        const std::nothrow_t&)__THROW {
+  ShimCppDelete(ptr);
+}
+
+SHIM_ALWAYS_EXPORT void operator delete[](void* ptr,
+                                          const std::nothrow_t&) __THROW {
+  ShimCppDelete(ptr);
+}
+
+#else  // !OS_MACOSX
+
 SHIM_ALWAYS_EXPORT void* operator new(size_t size)
     SHIM_ALIAS_SYMBOL(ShimCppNew);
 
@@ -40,3 +80,5 @@ SHIM_ALWAYS_EXPORT void operator delete(void* p, const std::nothrow_t&) __THROW
 SHIM_ALWAYS_EXPORT void operator delete[](void* p,
                                           const std::nothrow_t&) __THROW
     SHIM_ALIAS_SYMBOL(ShimCppDelete);
+
+#endif  // OS_MACOSX