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

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 52ae322b52369a626dc11d301ee4ea4efe07971c..386cdd7c736b7b3f2d31334be496fafa3b7fd50a 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -3259,9 +3259,15 @@ void WebViewImpl::refreshPageScaleFactorAfterLayout()
 
 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);