Expose memory allocator internal stats and properties.

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 14dbc9e567fab312ac5abbda6cb5d2c40b9aa5ea..61d3b228be6cffbbc2dc02253874d0b9bc4a8ef7 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -466,6 +466,10 @@ class ContentMainRunnerImpl : public ContentMainRunner {
   }
 
 #if defined(USE_TCMALLOC)
+static bool GetPropertyThunk(const char* name, size_t* value) {
+  return MallocExtension::instance()->GetNumericProperty(name, value);
+}
+
 static void GetStatsThunk(char* buffer, int buffer_length) {
   MallocExtension::instance()->GetStats(buffer, buffer_length);
 }
@@ -504,6 +508,7 @@ static void ReleaseFreeMemoryThunk() {
     tc_set_new_mode(1);
 
     // On windows, we've already set these thunks up in _heap_init()
+    base::allocator::SetGetPropertyFunction(GetPropertyThunk);
     base::allocator::SetGetStatsFunction(GetStatsThunk);
     base::allocator::SetReleaseFreeMemoryFunction(ReleaseFreeMemoryThunk);