Add heap allocator usage to task profiler.

content/child/child_thread_impl.cc

Index: content/child/child_thread_impl.cc
diff --git a/content/child/child_thread_impl.cc b/content/child/child_thread_impl.cc
index 43fb48e0f81bdd9b93c83582693ac5772915217e..6d987cedce7343b0b6e9b3cae2bc3a556e3790ec 100644
--- a/content/child/child_thread_impl.cc
+++ b/content/child/child_thread_impl.cc
@@ -13,6 +13,7 @@
 #include "base/debug/alias.h"
 #include "base/debug/leak_annotations.h"
 #include "base/debug/profiler.h"
+#include "base/debug/scoped_thread_heap_usage.h"
 #include "base/lazy_instance.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ -794,6 +795,10 @@ void ChildThreadImpl::OnSetIPCLoggingEnabled(bool enable) {
 #endif  //  IPC_MESSAGE_LOG_ENABLED
 
 void ChildThreadImpl::OnSetProfilerStatus(ThreadData::Status status) {
+  if (status == ThreadData::PROFILING_ACTIVE &&
+      !base::debug::HeapUsageTracker::IsHeapTrackingEnabled()) {
+    base::debug::HeapUsageTracker::EnableHeapTracking();
+  }
   ThreadData::InitializeAndSetTrackingStatus(status);
 }