DevTools: Add showing viewport for Layers3DView.

Source/devtools/front_end/sdk/LayerTreeModel.js

Index: Source/devtools/front_end/sdk/LayerTreeModel.js
diff --git a/Source/devtools/front_end/sdk/LayerTreeModel.js b/Source/devtools/front_end/sdk/LayerTreeModel.js
index d76d2ca8a371a7f05ba84d0bbafd42296a476a04..e3c3408152e013099bf456dad1a936523da8f752 100644
--- a/Source/devtools/front_end/sdk/LayerTreeModel.js
+++ b/Source/devtools/front_end/sdk/LayerTreeModel.js
@@ -251,6 +251,22 @@ WebInspector.LayerTreeBase.prototype = {
         }
     },
 
+    /**
+     * @param {!Object} viewportSize
+     */
+    setViewportSize: function(viewportSize)
+    {
+        this._viewportSize = viewportSize;
+    },
+
+    /**
+     * @return {!Object | undefined}
+     */
+    viewportSize: function()
+    {
+        return this._viewportSize;
+    },
+
     __proto__: WebInspector.TargetAwareObject.prototype
 };
 
@@ -1118,11 +1134,13 @@ WebInspector.DeferredAgentLayerTree.prototype = {
  * @extends {WebInspector.DeferredLayerTree}
  * @param {!WebInspector.Target} target
  * @param {!WebInspector.TracingLayerPayload} root
+ * @param {!Object} viewportSize
  */
-WebInspector.DeferredTracingLayerTree = function(target, root)
+WebInspector.DeferredTracingLayerTree = function(target, root, viewportSize)
 {
     WebInspector.DeferredLayerTree.call(this, target);
     this._root = root;
+    this._viewportSize = viewportSize;
 }
 
 WebInspector.DeferredTracingLayerTree.prototype = {
@@ -1133,6 +1151,7 @@ WebInspector.DeferredTracingLayerTree.prototype = {
     {
         var result = new WebInspector.TracingLayerTree(this._target);
         result.setLayers(this._root, callback.bind(null, result));
+        result.setViewportSize(this._viewportSize);

[caseq, 2014/06/16 16:11:06]

I'd rather have it set before layers, so that we avoid any races in case we
synchronously invoke the callback in setLayers() (the callback may cause update
with an old viewport in this case).

[malch, 2014/06/16 16:16:14]

Done.

     },
 
     __proto__: WebInspector.DeferredLayerTree.prototype