Enable startup profiling by Win x64 stack sampling profiler

chrome/browser/chrome_browser_main.h

Index: chrome/browser/chrome_browser_main.h
diff --git a/chrome/browser/chrome_browser_main.h b/chrome/browser/chrome_browser_main.h
index 1258b75605e29bbd9b23eaf750f406033623ec22..4ce3238ba7c6268b65b90e04a7c5dbc932009a2b 100644
--- a/chrome/browser/chrome_browser_main.h
+++ b/chrome/browser/chrome_browser_main.h
@@ -8,6 +8,7 @@
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/field_trial.h"
+#include "base/profiler/stack_sampling_profiler.h"
 #include "base/tracked_objects.h"
 #include "chrome/browser/chrome_browser_field_trials.h"
 #include "chrome/browser/chrome_process_singleton.h"
@@ -109,10 +110,8 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
   // Record time from process startup to present time in an UMA histogram.
   void RecordBrowserStartupTime();
 
-  // Records a time value to an UMA histogram in the context of the
-  // PreReadExperiment field-trial. This also reports to the appropriate
-  // sub-histogram (_PreRead(Enabled|Disabled)).
-  void RecordPreReadExperimentTime(const char* name, base::TimeDelta time);
+  // Create parameters for sampling stacks during startup.
+  static base::StackSamplingProfiler::SamplingParams GetStartupSamplingParams();
 
   // Methods for Main Message Loop -------------------------------------------
 
@@ -148,6 +147,10 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
   // Parts are deleted in the inverse order they are added.
   std::vector<ChromeBrowserMainExtraParts*> chrome_extra_parts_;
 
+  // A profiler that periodically samples stack traces. Used to sample startup
+  // behavior.
+  base::StackSamplingProfiler sampling_profiler_;
+
   // Members initialized after / released before main_message_loop_ ------------
 
   scoped_ptr<BrowserProcessImpl> browser_process_;