Profiler-instrumentation of the startup time.

chrome/app/chrome_main_delegate.cc

Index: chrome/app/chrome_main_delegate.cc
diff --git a/chrome/app/chrome_main_delegate.cc b/chrome/app/chrome_main_delegate.cc
index e17bf8128a60481133fadce18f5e95458de29590..1bf782f15ad7a3d829c3e8fa779a6095bc228797 100644
--- a/chrome/app/chrome_main_delegate.cc
+++ b/chrome/app/chrome_main_delegate.cc
@@ -15,6 +15,7 @@
 #include "base/path_service.h"
 #include "base/process/memory.h"
 #include "base/process/process_handle.h"
+#include "base/profiler/scoped_tracker.h"
 #include "base/strings/string_util.h"
 #include "build/build_config.h"
 #include "chrome/browser/chrome_content_browser_client.h"
@@ -971,3 +972,16 @@ ChromeMainDelegate::CreateContentUtilityClient() {
   return g_chrome_content_utility_client.Pointer();
 #endif
 }
+
+void ChromeMainDelegate::EnableProfilerRecording() {

[vadimt, 2015/03/12 17:54:56]

Rename to MaybeEnableProfilerRecording.

Or, make this function to return bool, and enable recording after at the
caller's location.

[yao, 2015/03/12 18:16:16]

How about still enable it inside the function, but return a bool to indicate if
it's enabled for real. 

+  switch (chrome::VersionInfo::GetChannel()) {
+  case chrome::VersionInfo::CHANNEL_UNKNOWN:

[vadimt, 2015/03/12 17:54:56]

Shift right.
(Are you using gil cl format, BTW?)

[yao, 2015/03/12 18:16:16]

Done.

+    case chrome::VersionInfo::CHANNEL_CANARY:
+      tracked_objects::ScopedTracker::Enable();

[vadimt, 2015/03/12 17:54:56]

break after this line.

[yao, 2015/03/12 18:16:16]

Done.

+    case chrome::VersionInfo::CHANNEL_DEV:
+    case chrome::VersionInfo::CHANNEL_BETA:
+    case chrome::VersionInfo::CHANNEL_STABLE:
+      // Don't enable instrumentation.
+      break;
+  }
+}