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 58dc14b2bc0dc7e8f8df1a49d545598071899aee..c44cc000d4e538e13521dc41fbf4d52d730feebb 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -413,6 +413,10 @@ 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);
 }
@@ -451,6 +455,7 @@ 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);