blink: Enable the GPU trigger when viewport meta tag is not read

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 3241 matching lines @@
     updateLayerTreeViewport();
 
     // Relayout immediately to avoid violating the rule that needsLayout()
     // isn't set at the end of a layout.
     if (view->needsLayout())
         view->layout();
 }
 
 void WebViewImpl::updatePageDefinedViewportConstraints(const ViewportDescription& description)
 {
-    if (!settings()->viewportEnabled() || !page() || (!m_size.width && !m_size.height) || !page()->mainFrame()->isLocalFrame())
+    if (!settings()->viewportEnabled() || !page() || (!m_size.width && !m_size.height) || !page()->mainFrame()->isLocalFrame()) {
+        // If we're not reading the viewport meta tag, allow GPU rasterization.
+        if (!settingsImpl()->viewportMetaEnabled()) {

[ajuma, 2014/12/17 20:36:16]

WebSettingsImpl will still need this method added to it.

+            m_matchesHeuristicsForGpuRasterization = true;
+            if (m_layerTreeView)
+                m_layerTreeView->heuristicsForGpuRasterizationUpdated(m_matchesHeuristicsForGpuRasterization);
+        }
         return;
-
+    }
     Document* document = page()->deprecatedLocalMainFrame()->document();
 
     m_matchesHeuristicsForGpuRasterization = description.maxWidth == Length(DeviceWidth);
     if (m_layerTreeView)
         m_layerTreeView->heuristicsForGpuRasterizationUpdated(m_matchesHeuristicsForGpuRasterization);
 
     Length defaultMinWidth = document->viewportDefaultMinWidth();
     if (defaultMinWidth.isAuto())
         defaultMinWidth = Length(ExtendToZoom);
 
@@ skipping 1245 matching lines @@
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 void WebViewImpl::forceNextWebGLContextCreationToFail()
 {
     WebGLRenderingContext::forceNextWebGLContextCreationToFail();
 }
 
 } // namespace blink