Fix blurry content after disabling dev tools emulation

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index 72326e93daf0387e933ef84ec0a30ccde5f7c4fb..a9cef586d2a353d63e0c6f0547b6f3c68bb1e230 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -3981,15 +3981,16 @@ void WebViewImpl::setCompositorDeviceScaleFactorOverride(
     updateLayerTreeDeviceScaleFactor();
 }
 
-void WebViewImpl::setRootLayerTransform(const TransformationMatrix& transform) {
-  if (transform == m_rootLayerTransform)
+void WebViewImpl::setDeviceEmulationTransform(
+    const TransformationMatrix& transform) {
+  if (transform == m_deviceEmulationTransform)
     return;
-  m_rootLayerTransform = transform;
-  updateRootLayerTransform();
+  m_deviceEmulationTransform = transform;
+  updateDeviceEmulationTransform();
 }
 
 TransformationMatrix WebViewImpl::getRootLayerTransformForTesting() const {
-  return m_rootLayerTransform;
+  return m_deviceEmulationTransform;
 }
 
 void WebViewImpl::enableDeviceEmulation(
@@ -4394,7 +4395,7 @@ void WebViewImpl::setRootGraphicsLayer(GraphicsLayer* graphicsLayer) {
     m_rootGraphicsLayer = visualViewport.rootGraphicsLayer();
     m_visualViewportContainerLayer = visualViewport.containerLayer();
     m_rootLayer = m_rootGraphicsLayer->platformLayer();
-    updateRootLayerTransform();
+    updateDeviceEmulationTransform();
     m_layerTreeView->setRootLayer(*m_rootLayer);
     // We register viewport layers here since there may not be a layer
     // tree view prior to this point.
@@ -4576,9 +4577,15 @@ void WebViewImpl::updateLayerTreeDeviceScaleFactor() {
   m_layerTreeView->setDeviceScaleFactor(deviceScaleFactor);
 }
 
-void WebViewImpl::updateRootLayerTransform() {
-  if (m_visualViewportContainerLayer)
-    m_visualViewportContainerLayer->setTransform(m_rootLayerTransform);
+void WebViewImpl::updateDeviceEmulationTransform() {

[enne (OOO), 2016/10/03 23:27:30]

Renamed this as devtools is the only consumer of this function so that I could
put the recalculate raster scale call inside of here.

+  if (!m_visualViewportContainerLayer)
+    return;
+
+  // When the device emulation transform is updated, to avoid incorrect
+  // scales and fuzzy raster from the compositor, force all content to
+  // pick ideal raster scales.
+  m_visualViewportContainerLayer->setTransform(m_deviceEmulationTransform);
+  m_layerTreeView->forceRecalculateRasterScales();
 }
 
 bool WebViewImpl::detectContentOnTouch(