Merge tcmalloc r111 (perftools v. 1.8) with the chromium/ branch.

third_party/tcmalloc/chromium/src/google/malloc_hook.h

Index: third_party/tcmalloc/chromium/src/google/malloc_hook.h
===================================================================
--- third_party/tcmalloc/chromium/src/google/malloc_hook.h	(revision 94429)
+++ third_party/tcmalloc/chromium/src/google/malloc_hook.h	(working copy)
@@ -81,6 +81,14 @@
 # endif
 #endif
 
+// The C++ methods below call the C version (MallocHook_*), and thus
+// convert between an int and a bool.  Windows complains about this
+// (a "performance warning") which we don't care about, so we suppress.
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable:4800)
+#endif
+
 // Note: malloc_hook_c.h defines MallocHook_*Hook and
 // MallocHook_{Add,Remove}*Hook.  The version of these inside the MallocHook
 // class are defined in terms of the malloc_hook_c version.  See malloc_hook_c.h
@@ -342,4 +350,9 @@
   static void InvokeSbrkHookSlow(const void* result, std::ptrdiff_t increment);
 };
 
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+
 #endif /* _MALLOC_HOOK_H_ */