[Android] Support startup histogram.

chrome/common/startup_metric_utils.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_COMMON_STARTUP_METRIC_UTILS_H_
 #define CHROME_COMMON_STARTUP_METRIC_UTILS_H_
 
 #include <string>
 
 #include "base/time/time.h"
@@ skipping 13 matching lines @@
 // Note on usage: This function is idempotent and its overhead is low enough
 // in comparison with UI display that it's OK to call it on every
 // UI invocation regardless of whether the browser window has already
 // been displayed or not.
 void SetNonBrowserUIDisplayed();
 
 // Call this as early as possible in the startup process to record a
 // timestamp.
 void RecordMainEntryPointTime();
 
+#if defined(OS_ANDROID)
+// On Android the entry point time is the time at which the Java code starts.
+// This is recorded on the Java side, and then passed to the C++ side once the
+// C++ library is loaded and running.
+void RecordSavedMainEntryPointTime(const base::Time& entry_point_time);
+#endif // OS_ANDROID
+
 // Called just before the message loop is about to start. Entry point to record
 // startup stats.
 // |is_first_run| - is the current launch part of a first run.
 void OnBrowserStartupComplete(bool is_first_run);
 
 // Called when the initial page load has finished in order to record startup
 // stats.
 void OnInitialPageLoadComplete();
 
 // Scoper that records the time period before it's destructed in a histogram
@@ skipping 10 matching lines @@
  private:
   const base::TimeTicks start_time_;
   const std::string histogram_name_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedSlowStartupUMA);
 };
 
 }  // namespace startup_metric_utils
 
 #endif  // CHROME_COMMON_STARTUP_METRIC_UTILS_H_