Report memory retained by memory allocator internals.

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 22115ced37a5837dade8ddbcc6e1cd092ea82065..3f7d0e785af5c68d2d6e35cfff54dc5c380d9575 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -483,8 +483,19 @@ class ContentMainRunnerImpl : public ContentMainRunner {
   }
 
 #if defined(USE_TCMALLOC)
-static bool GetPropertyThunk(const char* name, size_t* value) {
-  return MallocExtension::instance()->GetNumericProperty(name, value);
+static bool GetAllocatorWasteSizeThunk(size_t* size) {
+  size_t heap_size, allocated_bytes, unmapped_bytes;
+  MallocExtension* ext = MallocExtension::instance();
+  if (ext->GetNumericProperty("generic.heap_size", &heap_size) &&
+      ext->GetNumericProperty("generic.current_allocated_bytes",
+                              &allocated_bytes) &&
+      ext->GetNumericProperty("tcmalloc.pageheap_unmapped_bytes",
+                              &unmapped_bytes)) {
+    *size = heap_size - allocated_bytes - unmapped_bytes;
+    return true;
+  }
+  DCHECK(false);
+  return false;
 }
 
 static void GetStatsThunk(char* buffer, int buffer_length) {
@@ -532,7 +543,8 @@ 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::SetGetAllocatorWasteSizeFunction(
+        GetAllocatorWasteSizeThunk);
     base::allocator::SetGetStatsFunction(GetStatsThunk);
     base::allocator::SetReleaseFreeMemoryFunction(ReleaseFreeMemoryThunk);