Record Chrome trace events in tcmalloc heap profiles

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 5f99db5e32efe22f57866734d45d48f4e8bbd01f..49a6fff1979b4433d4124b8d494786a73d780438 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -474,6 +474,9 @@ void BrowserMainLoop::MainMessageLoopStart() {
     memory_observer_.reset(new MemoryObserver());
     base::MessageLoop::current()->AddTaskObserver(memory_observer_.get());
   }
+
+  trace_memory_controller_.reset(new base::debug::TraceMemoryController(
+      base::MessageLoop::current()->message_loop_proxy()));
 }
 
 void BrowserMainLoop::CreateThreads() {
@@ -646,6 +649,8 @@ void BrowserMainLoop::ShutdownThreadsAndCleanUp() {
   if (parts_)
     parts_->PostMainMessageLoopRun();
 
+  trace_memory_controller_.reset();
+
 #if !defined(OS_IOS)
   // Destroying the GpuProcessHostUIShims on the UI thread posts a task to
   // delete related objects on the GPU thread. This must be done before