base: Do not allow MessagePumpObservers to consume events.

chrome/browser/jankometer_win.cc

 // 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.
 
 #include "chrome/browser/jankometer.h"
 
 #include <limits>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 280 matching lines @@
       return;
     base::TimeTicks now = base::TimeTicks::Now();
     const base::TimeDelta queueing_time = now - pending_task.time_posted;
     helper_.StartProcessingTimers(queueing_time);
   }
 
   virtual void DidProcessTask(const base::PendingTask& pending_task) OVERRIDE {
     helper_.EndProcessingTimers();
   }
 
-  virtual base::EventStatus WillProcessEvent(
-      const base::NativeEvent& event) OVERRIDE {
+  virtual void WillProcessEvent(const base::NativeEvent& event) OVERRIDE {
     if (!helper_.MessageWillBeMeasured())
-      return base::EVENT_CONTINUE;
+      return;
     // GetMessageTime returns a LONG (signed 32-bit) and GetTickCount returns
     // a DWORD (unsigned 32-bit). They both wrap around when the time is longer
     // than they can hold. I'm not sure if GetMessageTime wraps around to 0,
     // or if the original time comes from GetTickCount, it might wrap around
     // to -1.
     //
     // Therefore, I cast to DWORD so if it wraps to -1 we will correct it. If
     // it doesn't, then our time delta will be negative if a message happens
     // to straddle the wraparound point, it will still be OK.
     DWORD cur_message_issue_time = static_cast<DWORD>(event.time);
     DWORD cur_time = GetTickCount();
     base::TimeDelta queueing_time =
         base::TimeDelta::FromMilliseconds(cur_time - cur_message_issue_time);
 
     helper_.StartProcessingTimers(queueing_time);
-    return base::EVENT_CONTINUE;
   }
 
   virtual void DidProcessEvent(const base::NativeEvent& event) OVERRIDE {
     helper_.EndProcessingTimers();
   }
 
  private:
   friend class base::RefCountedThreadSafe<UIJankObserver>;
 
   virtual ~UIJankObserver() {}
@@ skipping 56 matching lines @@
     delete ui_observer;
     ui_observer = NULL;
   }
   if (io_observer) {
     // IO thread can't be running when we remove observers.
     DCHECK((!g_browser_process) || !(g_browser_process->io_thread()));
     delete io_observer;
     io_observer = NULL;
   }
 }