Revert of Change WebContents::last_active_time_ to Time instead of Timeticks.

content/public/browser/web_contents.h

Index: content/public/browser/web_contents.h
diff --git a/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
index d5ed42f6d334f41ecffa91cfae4295cad4a7a23f..62f09a8f47ca151e0743309be0a58979b8dcdeb6 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -32,7 +32,7 @@
 
 namespace base {
 class DictionaryValue;
-class Time;
+class TimeTicks;
 }
 
 namespace blink {
@@ -353,7 +353,7 @@
 
   // Get the last time that the WebContents was made active (either when it was
   // created or shown with WasShown()).
-  virtual base::Time GetLastActiveTime() const = 0;
+  virtual base::TimeTicks GetLastActiveTime() const = 0;
 
   // Invoked when the WebContents becomes shown/hidden.
   virtual void WasShown() = 0;