cc: When the transform's scale is unknown, draw render surfaces at the resolution of the screen.

cc/layer_tree_host_common.cc

Index: cc/layer_tree_host_common.cc
diff --git a/cc/layer_tree_host_common.cc b/cc/layer_tree_host_common.cc
index b9fc38083f32150ab968b4c6e0e2770216c7a2be..d0a63728b3cd073b31f6640cb9516d66be8edaa5 100644
--- a/cc/layer_tree_host_common.cc
+++ b/cc/layer_tree_host_common.cc
@@ -390,7 +390,7 @@ static inline void updateLayerContentsScale(Layer* layer, const gfx::Transform&
         rasterScale = 1;
 
         if (!animatingTransformToScreen && layer->automaticallyComputeRasterScale()) {
-            gfx::Vector2dF transformScale = MathUtil::computeTransform2dScaleComponents(combinedTransform);
+            gfx::Vector2dF transformScale = MathUtil::computeTransform2dScaleComponents(combinedTransform, 0.f);

[danakj, 2012/12/20 23:27:12]

Now switch to 0.f so we don't save it when we don't know the scale. Thanks :)

             float combinedScale = std::max(transformScale.x(), transformScale.y());
             rasterScale = combinedScale / deviceScaleFactor;
             if (!layer->boundsContainPageScale())
@@ -660,7 +660,7 @@ static void calculateDrawPropertiesInternal(LayerType* layer, const gfx::Transfo
     gfx::Transform nextHierarchyMatrix = fullHierarchyMatrix;
     gfx::Transform sublayerMatrix;
 
-    gfx::Vector2dF renderSurfaceSublayerScale = MathUtil::computeTransform2dScaleComponents(combinedTransform);
+    gfx::Vector2dF renderSurfaceSublayerScale = MathUtil::computeTransform2dScaleComponents(combinedTransform, deviceScaleFactor * pageScaleFactor);
 
     if (subtreeShouldRenderToSeparateSurface(layer, combinedTransform.IsScaleOrTranslation())) {
         // Check back-face visibility before continuing with this surface and its subtree