Adding momentum/overscroll to views:: ScrollViews

cc/proto/layer.proto

 // Copyright 2015 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.
 
 syntax = "proto2";
 
 import "layer_position_constraint.proto";
 import "point3f.proto";
 import "pointf.proto";
 import "recording_source.proto";
@@ skipping 49 matching lines @@
   // for their specific properties.
   optional BaseLayerProperties base = 5;
 
   // Only one of these fields may be set per LayerProperties.
   // TODO(dtrainor): use a 'oneof' union when it's supported in Chromium.  See
   // crbug.com/570371.
   optional PictureLayerProperties picture = 6;
   optional SolidColorScrollbarLayerProperties solid_scrollbar = 7;
 }
 
-// NEXT ID: 55
+// NEXT ID: 57
 message BaseLayerProperties {
   optional Point3F transform_origin = 1;
   optional uint32 background_color = 2;
   optional uint32 safe_opaque_background_color = 53;
   optional Size bounds = 3;
   optional int64 transform_free_index = 4;
   optional int64 effect_tree_index = 5;
   optional int64 clip_tree_index = 6;
   optional int64 scroll_tree_index = 50;
   optional Vector2dF offset_to_transform_parent = 7;
@@ skipping 34 matching lines @@
   optional bool user_scrollable_horizontal = 38;
   optional bool user_scrollable_vertical = 39;
 
   optional int32 scroll_parent_id = 40;
   repeated int32 scroll_children_ids = 41;
 
   optional int32 clip_parent_id = 42;
   repeated int32 clip_children_ids = 43;
 
   optional ScrollOffset scroll_offset = 44;
+  optional ScrollOffset overscroll = 55;
+  optional bool can_overscroll = 56;
 
   optional Rect update_rect = 46;
 
   // TODO(nyquist): Figure out what to do with LayerAnimationController.
   // optional LayerAnimationController layer_animation_controller = ???;
 }
 
 message PictureLayerProperties {
   optional RecordingSource recording_source = 1;
   optional Region invalidation = 2;
   optional Rect last_updated_visible_layer_rect = 3;
   optional bool is_mask = 4;
   optional bool nearest_neighbor = 5;
 
   optional int64 update_source_frame_number = 6;
 }
 
 message SolidColorScrollbarLayerProperties {
   enum ScrollbarOrientation {
     HORIZONTAL = 0;
     VERTICAL = 1;
   };
 
   optional int32 scroll_layer_id = 1;
   optional int32 thumb_thickness = 2;
   optional int32 track_start = 3;
   optional bool is_left_side_vertical_scrollbar = 4;
   optional ScrollbarOrientation orientation = 5;
 }