Implement desktop compatibility viewport

cc/layer_tree_host_common.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layer_tree_host_common.h"
 
 #include <algorithm>
 
 #include "base/debug/trace_event.h"
 #include "cc/layer.h"
@@ skipping 320 matching lines @@
     // pre-multiply any fixed-position layer's drawTransform to undo the scrollDeltas -- as long as
     // that fixed position layer is fixed onto the same renderTarget as this scrollingLayer.
     //
 
     gfx::Transform partialLayerOriginTransform = parentMatrix;
     partialLayerOriginTransform.PreconcatTransform(scrollingLayer->implTransform());
 
     gfx::Transform scrollCompensationForThisLayer = partialLayerOriginTransform; // Step 3
     scrollCompensationForThisLayer.Translate(scrollingLayer->scrollDelta().x(), scrollingLayer->scrollDelta().y()); // Step 2
 
+    gfx::Vector2dF desktopCompatibilityViewportDelta = scrollingLayer->desktopCompatibilityViewportOffsetFromScrollPositionDelta();
+    scrollCompensationForThisLayer.Translate(desktopCompatibilityViewportDelta.x(), desktopCompatibilityViewportDelta.y());
+
+    {
+        gfx::Vector2dF tmp = scrollingLayer->desktopCompatibilityViewportOffsetFromScrollPosition();
+        gfx::Vector2dF tmp2 = scrollingLayer->desktopCompatibilityViewportOffsetFromScrollPositionDelta();
+        fprintf (stderr, "offset: %f %f\n", tmp.x(), tmp.y());
+        fprintf (stderr, "delta : %f %f\n", tmp2.x(), tmp2.y());
+    }
+
     gfx::Transform inversePartialLayerOriginTransform(gfx::Transform::kSkipInitialization);
     if (!partialLayerOriginTransform.GetInverse(&inversePartialLayerOriginTransform)) {
         // TODO(shawnsingh): Either we need to handle uninvertible transforms
         // here, or DCHECK that the transform is invertible.
     }
     scrollCompensationForThisLayer.PreconcatTransform(inversePartialLayerOriginTransform); // Step 1
     return scrollCompensationForThisLayer;
 }
 
 gfx::Transform computeScrollCompensationMatrixForChildren(Layer* currentLayer, const gfx::Transform& currentParentMatrix, const gfx::Transform& currentScrollCompensation)
@@ skipping 832 matching lines @@
 
   // At this point, we think the point does hit the touch event handler region on the layer, but we need to walk up
   // the parents to ensure that the layer was not clipped in such a way that the
   // hit point actually should not hit the layer.
   if (pointIsClippedBySurfaceOrClipRect(screenSpacePoint, layerImpl))
      return false;
 
   return true;
 }
 }  // namespace cc