Refactor browser process coordinate transformation methods

content/browser/frame_host/cross_process_frame_connector.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_
 #define CONTENT_BROWSER_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_
 
 #include <stdint.h>
 
 #include "cc/output/compositor_frame.h"
@@ skipping 79 matching lines @@
   virtual void SetChildFrameSurface(const cc::SurfaceId& surface_id,
                                     const gfx::Size& frame_size,
                                     float scale_factor,
                                     const cc::SurfaceSequence& sequence);
 
   gfx::Rect ChildFrameRect();
   float device_scale_factor() const { return device_scale_factor_; }
   void GetScreenInfo(blink::WebScreenInfo* results);
   void UpdateCursor(const WebCursor& cursor);
   gfx::Point TransformPointToRootCoordSpace(const gfx::Point& point,
-                                            cc::SurfaceId surface_id);
+                                            const cc::SurfaceId& surface_id);
+  // TransformPointToLocalCoordSpace() can only transform points between
+  // surfaces where one is embedded (not necessarily directly) within the
+  // other. For points that can be in sibling surfaces, they must first be
+  // converted to the root surface's coordinate space.
+  gfx::Point TransformPointToLocalCoordSpace(
+      const gfx::Point& point,
+      const cc::SurfaceId& original_surface,
+      const cc::SurfaceId& local_surface_id);
+  gfx::Point TransformPointToCoordSpaceForView(

[nasko, 2016/07/27 22:52:13]

bikeshed: TransformPointToViewCoordSpace? Since you have the pattern of
TransformPointTo(...)CoordSpace.

[kenrb, 2016/07/28 16:24:37]

I feel like it is slightly more intuitive as it is. 'RootCoordSpace' and
'LocalCoordSpace' should be obvious, but I think 'CoordSpaceForView' conveys a
little better that the coordinate space target is an argument and not something
already known to the callee.

+      const gfx::Point& point,
+      RenderWidgetHostViewBase* target_view,
+      const cc::SurfaceId& local_surface_id);
+
   // Pass acked touch events to the root view for gesture processing.
   void ForwardProcessAckedTouchEvent(const TouchEventWithLatencyInfo& touch,
                                      InputEventAckState ack_result);
   // Gesture events with unused scroll deltas must be bubbled to ancestors
   // who may consume the delta.
   void BubbleScrollEvent(const blink::WebGestureEvent& event);
 
   // Determines whether the root RenderWidgetHostView (and thus the current
   // page) has focus.
   bool HasFocus();
@@ skipping 40 matching lines @@
   gfx::Rect child_frame_rect_;
   float device_scale_factor_;
 
   bool is_scroll_bubbling_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_