Support bottom-right anchored fixed-position elements during a pinch gesture

webkit/compositor_bindings/web_layer_impl.cc

Index: webkit/compositor_bindings/web_layer_impl.cc
diff --git a/webkit/compositor_bindings/web_layer_impl.cc b/webkit/compositor_bindings/web_layer_impl.cc
index 7adb2f10ec8e02181ef5c78e7af5ca3352cd6486..f68d7c5f297fdcd438511aa479119292ee58f0e2 100644
--- a/webkit/compositor_bindings/web_layer_impl.cc
+++ b/webkit/compositor_bindings/web_layer_impl.cc
@@ -10,6 +10,7 @@
 #include "cc/layers/layer.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebFloatPoint.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebFloatRect.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebLayerPositionConstraint.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebSize.h"
 #include "third_party/skia/include/utils/SkMatrix44.h"
 #include "webkit/compositor_bindings/web_animation_impl.h"
@@ -311,12 +312,13 @@ bool WebLayerImpl::isContainerForFixedPositionLayers() const {
   return layer_->is_container_for_fixed_position_layers();
 }
 
-void WebLayerImpl::setFixedToContainerLayer(bool enable) {
-  layer_->SetFixedToContainerLayer(enable);
+void WebLayerImpl::setPositionConstraint(
+    const WebKit::WebLayerPositionConstraint& constraint) {
+  layer_->SetPositionConstraint(constraint);
 }
 
-bool WebLayerImpl::fixedToContainerLayer() const {
-  return layer_->fixed_to_container_layer();
+WebKit::WebLayerPositionConstraint WebLayerImpl::positionConstraint() const {
+  return layer_->position_constraint();
 }
 
 void WebLayerImpl::setScrollClient(