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

cc/layers/layer_position_constraint.cc

Index: cc/layers/layer_position_constraint.cc
diff --git a/cc/layers/layer_position_constraint.cc b/cc/layers/layer_position_constraint.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d18fbe9dece4f21649b22ec38587d4c07baf8627
--- /dev/null
+++ b/cc/layers/layer_position_constraint.cc
@@ -0,0 +1,48 @@
+// Copyright 2013 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/layers/layer_position_constraint.h"
+
+#include "third_party/WebKit/Source/Platform/chromium/public/WebLayerPositionConstraint.h"
+
+using WebKit::WebLayerPositionConstraint;
+
+namespace cc {
+
+LayerPositionConstraint::LayerPositionConstraint()
+    : is_fixed_position_(false),
+      is_fixed_to_right_edge_(false),
+      is_fixed_to_bottom_edge_(false) {
+}
+
+LayerPositionConstraint::LayerPositionConstraint(
+    const WebLayerPositionConstraint& constraint)
+    : is_fixed_position_(constraint.isFixedPosition),
+      is_fixed_to_right_edge_(constraint.isFixedToRightEdge),
+      is_fixed_to_bottom_edge_(constraint.isFixedToBottomEdge) {
+}
+
+bool LayerPositionConstraint::operator==(
+    const LayerPositionConstraint& other) const {
+  if (!is_fixed_position_ && !other.is_fixed_position_)
+    return true;
+  return is_fixed_position_ == other.is_fixed_position_ &&
+          is_fixed_to_right_edge_ == other.is_fixed_to_right_edge_ &&
+          is_fixed_to_bottom_edge_ == other.is_fixed_to_bottom_edge_;
+}
+
+bool LayerPositionConstraint::operator!=(
+    const LayerPositionConstraint& other) const {
+  return !(*this == other);
+}
+
+LayerPositionConstraint::operator WebLayerPositionConstraint() const {
+  WebLayerPositionConstraint constraint;
+  constraint.isFixedPosition = is_fixed_position_;
+  constraint.isFixedToRightEdge = is_fixed_to_right_edge_;
+  constraint.isFixedToBottomEdge = is_fixed_to_bottom_edge_;
+  return constraint;
+}
+
+}  // namespace cc