Don't restart the ImageQualityController timer unless it is already half over.

third_party/WebKit/Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 426 matching lines @@
     , m_baseBackgroundColor(Color::white)
     , m_backgroundColorOverride(Color::transparent)
     , m_zoomFactorOverride(0)
     , m_userGestureObserved(false)
     , m_shouldDispatchFirstVisuallyNonEmptyLayout(false)
     , m_shouldDispatchFirstLayoutAfterFinishedParsing(false)
     , m_shouldDispatchFirstLayoutAfterFinishedLoading(false)
     , m_displayMode(WebDisplayModeBrowser)
     , m_elasticOverscroll(FloatSize())
     , m_scheduler(adoptPtr(Platform::current()->currentThread()->scheduler()->createWebViewScheduler(this).release()))
+    , m_lastFrameTimeMonotonic(0)
 {
     Page::PageClients pageClients;
     pageClients.chromeClient = m_chromeClientImpl.get();
     pageClients.contextMenuClient = &m_contextMenuClientImpl;
     pageClients.editorClient = &m_editorClientImpl;
     pageClients.spellCheckerClient = &m_spellCheckerClientImpl;
 
     m_page = Page::createOrdinary(pageClients);
     MediaKeysController::provideMediaKeysTo(*m_page, &m_mediaKeysClientImpl);
     provideSpeechRecognitionTo(*m_page, SpeechRecognitionClientProxy::create(client ? client->speechRecognizer() : nullptr));
@@ skipping 1495 matching lines @@
                 IntSize(), 0, PlatformEvent::NoModifiers, lastFlingSourceDevice == WebGestureDeviceTouchpad ? PlatformGestureSourceTouchpad : PlatformGestureSourceTouchscreen);
             endScrollEvent.setScrollGestureData(0, 0, ScrollByPrecisePixel, 0, 0, true, false, -1 /* null plugin id */);
 
             mainFrameImpl()->frame()->eventHandler().handleGestureScrollEnd(endScrollEvent);
         }
     }
 
     if (!mainFrameImpl())
         return;
 
+    m_lastFrameTimeMonotonic = lastFrameTimeMonotonic;
+
     DocumentLifecycle::AllowThrottlingScope throttlingScope(mainFrameImpl()->frame()->document()->lifecycle());
     PageWidgetDelegate::animate(*m_page, lastFrameTimeMonotonic);
 }
 
 void WebViewImpl::updateAllLifecyclePhases()
 {
     TRACE_EVENT0("blink", "WebViewImpl::updateAllLifecyclePhases");
     if (!mainFrameImpl())
         return;
 
@@ skipping 2595 matching lines @@
 {
     // TODO(oshima): Investigate if this should return the ScreenInfo's scale factor rather than
     // page's scale factor, which can be 1 in use-zoom-for-dsf mode.
     if (!page())
         return 1;
 
     return page()->deviceScaleFactor();
 }
 
 } // namespace blink