Update touch selection to only modify one selection point at a time.

content/browser/renderer_host/input/touch_selection_controller.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_RENDERER_HOST_INPUT_TOUCH_SELECTION_CONTROLLER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_SELECTION_CONTROLLER_H_
 
 #include "cc/output/viewport_selection_bound.h"
 #include "content/browser/renderer_host/input/selection_event_type.h"
 #include "content/browser/renderer_host/input/touch_handle.h"
@@ skipping 13 matching lines @@
 
 // Interface through which |TouchSelectionController| issues selection-related
 // commands, notifications and requests.
 class CONTENT_EXPORT TouchSelectionControllerClient {
  public:
   virtual ~TouchSelectionControllerClient() {}
 
   virtual bool SupportsAnimation() const = 0;
   virtual void SetNeedsAnimate() = 0;
   virtual void MoveCaret(const gfx::PointF& position) = 0;
+  virtual void MoveSelectionExtent(const gfx::PointF& position) = 0;
   virtual void SelectBetweenCoordinates(const gfx::PointF& start,

[jdduke (slow), 2014/10/15 15:46:07]

While you're digging around here, maybe we could rename all of the
|SelectBetweenCoordinates| methods to |SelectRange(base, extent)|? Makes
grepping a lot easier to find all the connected paths =/

[christiank, 2014/10/17 14:33:05]

Sure, makes sense.

                                         const gfx::PointF& end) = 0;
   virtual void OnSelectionEvent(SelectionEventType event,
                                 const gfx::PointF& position) = 0;
   virtual scoped_ptr<TouchHandleDrawable> CreateDrawable() = 0;
 };
 
 // Controller for manipulating text selection via touch input.
 class CONTENT_EXPORT TouchSelectionController : public TouchHandleClient {
  public:
   TouchSelectionController(TouchSelectionControllerClient* client,
@@ skipping 81 matching lines @@
   cc::ViewportSelectionBound end_;
   TouchHandleOrientation start_orientation_;
   TouchHandleOrientation end_orientation_;
 
   scoped_ptr<TouchHandle> insertion_handle_;
   bool is_insertion_active_;
   bool activate_insertion_automatically_;
 
   scoped_ptr<TouchHandle> start_selection_handle_;
   scoped_ptr<TouchHandle> end_selection_handle_;
-  gfx::PointF fixed_handle_position_;
   bool is_selection_active_;
   bool activate_selection_automatically_;
 
   bool selection_empty_;
   bool selection_editable_;
 
   bool temporarily_hidden_;
 
   DISALLOW_COPY_AND_ASSIGN(TouchSelectionController);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_SELECTION_CONTROLLER_H_