Update from chromium https://crrev.com/301725/

base/profiler/scoped_profile.cc

Index: base/profiler/scoped_profile.cc
diff --git a/base/profiler/scoped_profile.cc b/base/profiler/scoped_profile.cc
index e1edc97357cc2726c074976e4e3467c56552899d..8b0ae59a44aa5ef7ce86e0aa28c6288ef9ca0465 100644
--- a/base/profiler/scoped_profile.cc
+++ b/base/profiler/scoped_profile.cc
@@ -13,20 +13,32 @@ namespace tracked_objects {
 
 ScopedProfile::ScopedProfile(const Location& location)
     : birth_(ThreadData::TallyABirthIfActive(location)) {
+  if (!birth_)
+    return;
+
   ThreadData::PrepareForStartOfRun(birth_);
+  stopwatch_.Start();
 }
 
-ScopedProfile::~ScopedProfile() {
-  StopClockAndTally();
-}
+ScopedProfile::ScopedProfile(const Location& location, Mode mode)
+    : birth_(NULL) {
+  if (mode == DISABLED)
+    return;
 
-void ScopedProfile::StopClockAndTally() {
-  stopwatch_.Stop();
+  birth_ = ThreadData::TallyABirthIfActive(location);
+  if (!birth_)
+    return;
+
+  ThreadData::PrepareForStartOfRun(birth_);
+  stopwatch_.Start();
+}
 
+ScopedProfile::~ScopedProfile() {
   if (!birth_)
     return;
+
+  stopwatch_.Stop();
   ThreadData::TallyRunInAScopedRegionIfTracking(birth_, stopwatch_);
-  birth_ = NULL;
 }
 
 }  // namespace tracked_objects