Update the tcmalloc chromium branch to r144 (gperftools 2.0), and merge chromium-specific changes.

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

Index: third_party/tcmalloc/chromium/src/gperftools/malloc_hook.h
diff --git a/third_party/tcmalloc/chromium/src/google/malloc_hook.h b/third_party/tcmalloc/chromium/src/gperftools/malloc_hook.h
similarity index 97%
copy from third_party/tcmalloc/chromium/src/google/malloc_hook.h
copy to third_party/tcmalloc/chromium/src/gperftools/malloc_hook.h
index f5575f13999f267d2351bdb29bbf228aec205193..673a3f36c198436de23b2d528c0d0e244586a07f 100644
--- a/third_party/tcmalloc/chromium/src/google/malloc_hook.h
+++ b/third_party/tcmalloc/chromium/src/gperftools/malloc_hook.h
@@ -69,7 +69,7 @@
 #include <stddef.h>
 #include <sys/types.h>
 extern "C" {
-#include <google/malloc_hook_c.h>  // a C version of the malloc_hook interface
+#include <gperftools/malloc_hook_c.h>  // a C version of the malloc_hook interface
 }
 
 // Annoying stuff for windows -- makes sure clients can import these functions
@@ -81,6 +81,14 @@ extern "C" {
 # 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 @@ class PERFTOOLS_DLL_DECL MallocHook {
   static void InvokeSbrkHookSlow(const void* result, std::ptrdiff_t increment);
 };
 
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+
 #endif /* _MALLOC_HOOK_H_ */