Revert of base: Remove use of MessageLoopProxy

base/trace_event/trace_event_memory.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 BASE_TRACE_EVENT_TRACE_EVENT_MEMORY_H_
 #define BASE_TRACE_EVENT_TRACE_EVENT_MEMORY_H_
 
 #include "base/base_export.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/timer/timer.h"
 #include "base/trace_event/trace_event_impl.h"
 
 // TODO(jamescook): Windows support for memory tracing.
 #if !defined(NO_TCMALLOC) && !defined(OS_NACL) && \
     (defined(OS_LINUX) || defined(OS_ANDROID))
 #define TCMALLOC_TRACE_MEMORY_SUPPORTED 1
 #endif
 
 namespace base {
 
-class SingleThreadTaskRunner;
+class MessageLoopProxy;
 
 namespace trace_event {
 
 // Watches for chrome://tracing to be enabled or disabled. When tracing is
 // enabled, also enables tcmalloc heap profiling. This class is the preferred
 // way to turn trace-base heap memory profiling on and off.
 class BASE_EXPORT TraceMemoryController
     : public TraceLog::EnabledStateObserver {
  public:
   typedef int (*StackGeneratorFunction)(int skip_count, void** stack);
   typedef void (*HeapProfilerStartFunction)(StackGeneratorFunction callback);
   typedef void (*HeapProfilerStopFunction)();
   typedef char* (*GetHeapProfileFunction)();
 
-  // |task_runner| must be a task runner for the primary thread for the client
+  // |message_loop_proxy| must be a proxy to the primary thread for the client
   // process, e.g. the UI thread in a browser. The function pointers must be
   // pointers to tcmalloc heap profiling functions; by avoiding direct calls to
   // these functions we avoid a dependency on third_party/tcmalloc from base.
-  TraceMemoryController(scoped_refptr<SingleThreadTaskRunner> task_runner,
-                        HeapProfilerStartFunction heap_profiler_start_function,
-                        HeapProfilerStopFunction heap_profiler_stop_function,
-                        GetHeapProfileFunction get_heap_profile_function);
+  TraceMemoryController(
+      scoped_refptr<MessageLoopProxy> message_loop_proxy,
+      HeapProfilerStartFunction heap_profiler_start_function,
+      HeapProfilerStopFunction heap_profiler_stop_function,
+      GetHeapProfileFunction get_heap_profile_function);
   virtual ~TraceMemoryController();
 
   // base::trace_event::TraceLog::EnabledStateChangedObserver overrides:
   void OnTraceLogEnabled() override;
   void OnTraceLogDisabled() override;
 
   // Starts heap memory profiling.
   void StartProfiling();
 
   // Captures a heap profile.
   void DumpMemoryProfile();
 
   // If memory tracing is enabled, dumps a memory profile to the tracing system.
   void StopProfiling();
 
  private:
   FRIEND_TEST_ALL_PREFIXES(TraceMemoryTest, TraceMemoryController);
 
   bool IsTimerRunningForTest() const;
 
   // Ensures the observer starts and stops tracing on the primary thread.
-  scoped_refptr<SingleThreadTaskRunner> task_runner_;
+  scoped_refptr<MessageLoopProxy> message_loop_proxy_;
 
   // Pointers to tcmalloc heap profiling functions. Allows this class to use
   // tcmalloc functions without introducing a dependency from base to tcmalloc.
   HeapProfilerStartFunction heap_profiler_start_function_;
   HeapProfilerStopFunction heap_profiler_stop_function_;
   GetHeapProfileFunction get_heap_profile_function_;
 
   // Timer to schedule memory profile dumps.
   RepeatingTimer<TraceMemoryController> dump_timer_;
 
@@ skipping 84 matching lines @@
 #else
 #define INTERNAL_TRACE_MEMORY(category, name)
 #endif  // defined(TRACE_MEMORY_SUPPORTED)
 
 // A special trace name that allows us to ignore memory allocations inside
 // the memory dump system itself. The allocations are recorded, but the
 // visualizer skips them. Must match the value in heap.js.
 #define TRACE_MEMORY_IGNORE "trace-memory-ignore"
 
 #endif  // BASE_TRACE_EVENT_TRACE_EVENT_MEMORY_H_