Tag some of Mojo heap allocations for the heap profiler.

mojo/public/cpp/bindings/connector.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_CONNECTOR_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_CONNECTOR_H_
 
 #include <memory>
 
 #include "base/callback.h"
@@ skipping 132 matching lines @@
   // callback.
   // It always returns false after CloseMessagePipe()/PassMessagePipe().
   bool during_sync_handle_watcher_callback() const {
     return sync_handle_watcher_callback_count_ > 0;
   }
 
   base::SingleThreadTaskRunner* task_runner() const {
     return task_runner_.get();
   }
 
+  // Sets the tag used by the heap profiler.
+  // |tag| must be a const string literal.
+  void SetWatcherHeapProfilerTag(const char* tag);
+
  private:
   // Callback of mojo::Watcher.
   void OnWatcherHandleReady(MojoResult result);
   // Callback of SyncHandleWatcher.
   void OnSyncHandleWatcherHandleReady(MojoResult result);
   void OnHandleReadyInternal(MojoResult result);
 
   void WaitToReadMore();
 
   // Returns false if it is impossible to receive more messages in the future.
@@ skipping 36 matching lines @@
   bool allow_woken_up_by_others_ = false;
   // If non-zero, currently the control flow is inside the sync handle watcher
   // callback.
   size_t sync_handle_watcher_callback_count_ = 0;
 
   base::ThreadChecker thread_checker_;
 
   base::Lock connected_lock_;
   bool connected_ = true;
 
+  // The tag used to track heap allocations that originated from a Watcher
+  // notification.
+  const char* heap_profiler_tag_ = nullptr;
+
   // Create a single weak ptr and use it everywhere, to avoid the malloc/free
   // cost of creating a new weak ptr whenever it is needed.
   // NOTE: This weak pointer is invalidated when the message pipe is closed or
   // transferred (i.e., when |connected_| is set to false).
   base::WeakPtr<Connector> weak_self_;
   base::WeakPtrFactory<Connector> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Connector);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_CONNECTOR_H_