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

content/browser/web_contents/web_contents_impl.cc

 // Copyright (c) 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.
 
 #include "content/browser/web_contents/web_contents_impl.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 3156 matching lines @@
 
   // TODO(avi): Remove. http://crbug.com/170921
   int type = is_loading ? NOTIFICATION_LOAD_START : NOTIFICATION_LOAD_STOP;
   NotificationDetails det = NotificationService::NoDetails();
   if (details)
       det = Details<LoadNotificationDetails>(details);
   NotificationService::current()->Notify(
       type, Source<NavigationController>(&controller_), det);
 }
 
-void WebContentsImpl::SelectRange(const gfx::Point& start,
-                                  const gfx::Point& end) {
+void WebContentsImpl::MoveRangeSelectionExtent(const gfx::Point& extent) {
+  RenderFrameHost* focused_frame = GetFocusedFrame();
+  if (!focused_frame)
+    return;
+
+  focused_frame->Send(new InputMsg_MoveRangeSelectionExtent(
+      focused_frame->GetRoutingID(), extent));
+}
+
+void WebContentsImpl::SelectRange(const gfx::Point& base,
+                                  const gfx::Point& extent) {
   RenderFrameHost* focused_frame = GetFocusedFrame();
   if (!focused_frame)
     return;
 
   focused_frame->Send(
-      new InputMsg_SelectRange(focused_frame->GetRoutingID(), start, end));
+      new InputMsg_SelectRange(focused_frame->GetRoutingID(), base, extent));
 }
 
 void WebContentsImpl::UpdateMaxPageIDIfNecessary(RenderViewHost* rvh) {
   // If we are creating a RVH for a restored controller, then we need to make
   // sure the RenderView starts with a next_page_id_ larger than the number
   // of restored entries.  This must be called before the RenderView starts
   // navigating (to avoid a race between the browser updating max_page_id and
   // the renderer updating next_page_id_).  Because of this, we only call this
   // from CreateRenderView and allow that to notify the RenderView for us.
   int max_restored_page_id = controller_.GetMaxRestoredPageID();
@@ skipping 1140 matching lines @@
   node->render_manager()->ResumeResponseDeferredAtStart();
 }
 
 void WebContentsImpl::SetForceDisableOverscrollContent(bool force_disable) {
   force_disable_overscroll_content_ = force_disable;
   if (view_)
     view_->SetOverscrollControllerEnabled(CanOverscrollContent());
 }
 
 }  // namespace content