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

cc/layers/layer_impl.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/layers/layer_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "base/stringprintf.h"
 #include "base/values.h"
 #include "cc/animation/animation_registrar.h"
@@ skipping 32 matching lines @@
       layer_surface_property_changed_(false),
       masks_to_bounds_(false),
       contents_opaque_(false),
       opacity_(1.0),
       preserves_3d_(false),
       use_parent_backface_visibility_(false),
       draw_checkerboard_for_missing_tiles_(false),
       draws_content_(false),
       force_render_surface_(false),
       is_container_for_fixed_position_layers_(false),
-      fixed_to_container_layer_(false),
       draw_depth_(0.f),
 #ifndef NDEBUG
       between_will_draw_and_did_draw_(false),
 #endif
       horizontal_scrollbar_layer_(NULL),
       vertical_scrollbar_layer_(NULL) {
   DCHECK_GT(layer_id_, 0);
   DCHECK(layer_tree_impl_);
   layer_tree_impl_->RegisterLayer(this);
   AnimationRegistrar* registrar = layer_tree_impl_->animationRegistrar();
@@ skipping 270 matching lines @@
   layer->SetMasksToBounds(masks_to_bounds_);
   layer->SetShouldScrollOnMainThread(should_scroll_on_main_thread_);
   layer->SetHaveWheelEventHandlers(have_wheel_event_handlers_);
   layer->SetNonFastScrollableRegion(non_fast_scrollable_region_);
   layer->SetTouchEventHandlerRegion(touch_event_handler_region_);
   layer->SetContentsOpaque(contents_opaque_);
   layer->SetOpacity(opacity_);
   layer->SetPosition(position_);
   layer->SetIsContainerForFixedPositionLayers(
       is_container_for_fixed_position_layers_);
-  layer->SetFixedToContainerLayer(fixed_to_container_layer_);
+  layer->SetFixedContainerSizeDelta(fixed_container_size_delta_);
+  layer->SetPositionConstraint(position_constraint_);
   layer->SetPreserves3d(preserves_3d());
   layer->SetUseParentBackfaceVisibility(use_parent_backface_visibility_);
   layer->SetSublayerTransform(sublayer_transform_);
   layer->SetTransform(transform_);
 
   layer->SetScrollable(scrollable_);
   layer->SetScrollOffset(scroll_offset_);
   layer->SetMaxScrollOffset(max_scroll_offset_);
 
   // If the main thread commits multiple times before the impl thread actually
@@ skipping 611 matching lines @@
   dict->Set("layer_quad", MathUtil::AsValue(layer_quad).release());
 }
 
 scoped_ptr<base::Value> LayerImpl::AsValue() const {
   scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue());
   AsValueInto(state.get());
   return state.PassAs<base::Value>();
 }
 
 }  // namespace cc