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 5312dcdbdfd33254c2ee3bda5d186fc542e7e017..ad1a28267b0616ad0dad30e937a9141f6507c804 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -3364,9 +3364,15 @@ 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.

[aelias_OOO_until_Jul13, 2015/02/28 01:13:33]

Could you move the new code to the top of this function, leaving the
early-return block as it was?  It's a bit confusing here because it has nothing
to do with some of the conditions like "!page()".

+        if (!settingsImpl()->viewportMetaEnabled()) {
+            m_matchesHeuristicsForGpuRasterization = true;
+            if (m_layerTreeView)
+                m_layerTreeView->heuristicsForGpuRasterizationUpdated(m_matchesHeuristicsForGpuRasterization);
+        }
         return;
-
+    }
     Document* document = page()->deprecatedLocalMainFrame()->document();
 
     m_matchesHeuristicsForGpuRasterization = description.maxWidth == Length(DeviceWidth)