Measure loading time of several tabs.

chrome/browser/automation/automation_provider_observers.h

Index: chrome/browser/automation/automation_provider_observers.h
diff --git a/chrome/browser/automation/automation_provider_observers.h b/chrome/browser/automation/automation_provider_observers.h
index 6481005412f376f41c54b79da178ff76b419d493..6bf6a2600938922ecd27b50116ab388bf6e465c8 100644
--- a/chrome/browser/automation/automation_provider_observers.h
+++ b/chrome/browser/automation/automation_provider_observers.h
@@ -36,7 +36,18 @@ class InitialLoadObserver : public NotificationObserver {
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
+  // Caller owns the return value and is responsible for deleting it.
+  // Example return value:
+  // {'tabs': [{'start_time_ms': 1, 'stop_time_ms': 2.5},
+  //           {'start_time_ms': 0.5, 'stop_time_ms': 3}]}
+  // stop_time_ms values may be null if WaitForInitialLoads has not finished.
+  // Only includes entries for the |tab_count| tabs we are monitoring.
+  // There is no defined ordering of the return value.
+  DictionaryValue* GetTimingInformation() const;
+
  private:
+  class TabTime;
+  typedef std::map<uintptr_t, TabTime> TabTimeMap;
   typedef std::set<uintptr_t> TabSet;
 
   void ConditionMet();
@@ -45,7 +56,8 @@ class InitialLoadObserver : public NotificationObserver {
 
   AutomationProvider* automation_;
   size_t outstanding_tab_count_;
-  TabSet loading_tabs_;
+  base::TimeTicks init_time_;
+  TabTimeMap loading_tabs_;
   TabSet finished_tabs_;
 
   DISALLOW_COPY_AND_ASSIGN(InitialLoadObserver);