cc: Refactor content scale/bounds into draw properties

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 4af5717b71987c790e4fba3a16999fbd1841d134..57a3e1065a726e83ec308cb1f127cb7f4b8356ea 100644
--- a/cc/layer_tree_host_common.cc
+++ b/cc/layer_tree_host_common.cc
@@ -364,8 +364,20 @@ gfx::Transform computeScrollCompensationMatrixForChildren(LayerImpl* layer, cons
     return nextScrollCompensationMatrix;
 }
 
-// There is no contentsScale on impl thread.
-static inline void updateLayerContentsScale(LayerImpl*, const gfx::Transform&, float, float, bool) { }
+static inline void updateLayerContentsScale(LayerImpl* layer, const gfx::Transform& combinedTransform, float deviceScaleFactor, float pageScaleFactor, bool animatingTransformToScreen)

[shawnsingh, 2012/12/11 21:54:05]

"update" was actually a word that really made me fumble at first.   It suddenly
makes the code feel not-so-one-way flow of data.

Could we please rename this (and the main thread version of this function) to
something like "calculateLayerContentsScale"?

[enne (OOO), 2012/12/11 23:23:44]

Sure, I can rename this.  Why is the word update problematic for you?

+{
+    gfx::Vector2dF transformScale = MathUtil::computeTransform2dScaleComponents(combinedTransform);
+    float contentsScale = std::max(transformScale.x(), transformScale.y());
+    layer->setIdealContentsScale(contentsScale);
+
+    LayerImpl* maskLayer = layer->maskLayer();
+    if (maskLayer)
+        maskLayer->setIdealContentsScale(contentsScale);
+
+    LayerImpl* replicaMaskLayer = layer->replicaLayer() ? layer->replicaLayer()->maskLayer() : 0;
+    if (replicaMaskLayer)
+        replicaMaskLayer->setIdealContentsScale(contentsScale);
+}
 
 static inline void updateLayerContentsScale(Layer* layer, const gfx::Transform& combinedTransform, float deviceScaleFactor, float pageScaleFactor, bool animatingTransformToScreen)
 {
@@ -390,15 +402,15 @@ static inline void updateLayerContentsScale(Layer* layer, const gfx::Transform&
     float contentsScale = rasterScale * deviceScaleFactor;
     if (!layer->boundsContainPageScale())
         contentsScale *= pageScaleFactor;
-    layer->setContentsScale(contentsScale);
+    layer->setIdealContentsScale(contentsScale);
 
     Layer* maskLayer = layer->maskLayer();
     if (maskLayer)
-        maskLayer->setContentsScale(contentsScale);
+        maskLayer->setIdealContentsScale(contentsScale);
 
     Layer* replicaMaskLayer = layer->replicaLayer() ? layer->replicaLayer()->maskLayer() : 0;
     if (replicaMaskLayer)
-        replicaMaskLayer->setContentsScale(contentsScale);
+        replicaMaskLayer->setIdealContentsScale(contentsScale);
 }
 
 // Recursively walks the layer tree starting at the given node and computes all the