WebLayerTreeView and WebWidget API cleanup

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 1889 matching lines @@
 void WebViewImpl::themeChanged()
 {
     if (!page())
         return;
     FrameView* view = page()->mainFrame()->view();
 
     WebRect damagedRect(0, 0, m_size.width, m_size.height);
     view->invalidateRect(damagedRect);
 }
 
-void WebViewImpl::setNeedsRedraw()
-{
-    if (m_layerTreeView && isAcceleratedCompositingActive())
-        m_layerTreeView->setNeedsRedraw();
-}
-
 void WebViewImpl::enterFullScreenForElement(WebCore::Element* element)
 {
     m_fullscreenController->enterFullScreenForElement(element);
 }
 
 void WebViewImpl::exitFullScreenForElement(WebCore::Element* element)
 {
     m_fullscreenController->exitFullScreenForElement(element);
 }
 
@@ skipping 1932 matching lines @@
             else
                 m_layerTreeView->clearViewportLayers();
         }
     }
 
     suppressInvalidations(false);
 }
 
 void WebViewImpl::scheduleCompositingLayerSync()
 {
-    m_layerTreeView->setNeedsRedraw();
+    m_layerTreeView->setNeedsAnimate();
 }
 
 void WebViewImpl::scrollRootLayerRect(const IntSize&, const IntRect&)
 {
     updateLayerTreeViewport();
 }
 
 void WebViewImpl::invalidateRect(const IntRect& rect)
 {
     if (m_isAcceleratedCompositingActive) {
@@ skipping 24 matching lines @@
         m_layerTreeView->registerForAnimations(layer);
 }
 
 WebCore::GraphicsLayer* WebViewImpl::rootGraphicsLayer()
 {
     return m_rootGraphicsLayer;
 }
 
 void WebViewImpl::scheduleAnimation()
 {
-    if (isAcceleratedCompositingActive() && Platform::current()->isThreadedCompositingEnabled()) {
+    if (isAcceleratedCompositingActive()) {
         ASSERT(m_layerTreeView);
         m_layerTreeView->setNeedsAnimate();
         return;
     }
     if (m_client)

[jamesr, 2013/11/21 23:59:33]

since m_client here is the RenderWidget which knows about compositing, can we
get rid of this branch completely and have RenderWidget always make the right
call on the cc::LayerTreeHost?  These branches and divergent codepaths exist
from a time when the content::RenderWidget didn't know anything about the
cc::LayerTreeHost and only the WebViewImpl knew about both (via
WebLayerTreeView), but that's not the situation any more

[trchen, 2013/11/22 00:15:32]

For single thread mode that would be an infinite recursion:

WebViewImpl::scheduleAnimation --> RenderWidget::scheduleAnimation -->
RenderWidgetCompositor::setNeedsAnimate --> LayerTreeHost::SetNeedsAnimate -->
SingleThreadProxy::SetNeedsAnimate --> RenderWidgetCompositor::ScheduleAnimation
--> RenderWidget::scheduleAnimation

The problem is that the first RenderWidget::scheduleAnimation means "the blink
engine wants to tell you there is an ongoing animation", and the latter
RenderWidget::scheduleAnimation means "so let's post AnimationCallback on the
task queue".

The solution would be renaming the existing scheduleAnimation to
postAnimationTask or something.

         m_client->scheduleAnimation();
 }
 
 void WebViewImpl::setIsAcceleratedCompositingActive(bool active)
 {
     blink::Platform::current()->histogramEnumeration("GPU.setIsAcceleratedCompositingActive", active * 2 + m_isAcceleratedCompositingActive, 4);
 
     if (m_isAcceleratedCompositingActive == active)
         return;
 
@@ skipping 248 matching lines @@
     const PageScaleConstraints& constraints = m_pageScaleConstraintsSet.pageDefinedConstraints();
 
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())
         return false;
 
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 } // namespace blink