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

content/browser/android/content_view_core_impl.h

 // Copyright 2012 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_ANDROID_CONTENT_VIEW_CORE_IMPL_H_
 #define CONTENT_BROWSER_ANDROID_CONTENT_VIEW_CORE_IMPL_H_
 
 #include <vector>
 
 #include "base/android/jni_android.h"
@@ skipping 252 matching lines @@
   // Methods called from native code
   // --------------------------------------------------------------------------
 
   gfx::Size GetPhysicalBackingSize() const;
   gfx::Size GetViewportSizeDip() const;
   float GetTopControlsLayoutHeightDip() const;
 
   void AttachLayer(scoped_refptr<cc::Layer> layer);
   void RemoveLayer(scoped_refptr<cc::Layer> layer);
 
-  void SelectBetweenCoordinates(const gfx::PointF& start,
-                                const gfx::PointF& end);
+  void MoveRangeSelectionExtent(const gfx::PointF& extent);
+
+  void SelectBetweenCoordinates(const gfx::PointF& base,
+                                const gfx::PointF& extent);
 
  private:
   class ContentViewUserData;
 
   friend class ContentViewUserData;
   virtual ~ContentViewCoreImpl();
 
   // WebContentsObserver implementation.
   virtual void RenderViewReady() override;
   virtual void RenderViewHostChanged(RenderViewHost* old_host,
@@ skipping 55 matching lines @@
       java_bridge_dispatcher_host_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentViewCoreImpl);
 };
 
 bool RegisterContentViewCore(JNIEnv* env);
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_CONTENT_VIEW_CORE_IMPL_H_