[WIP] Allow scroll events to permanently change the default gesture handler in RootView

chrome/browser/ui/views/tabs/tab_strip.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 "chrome/browser/ui/views/tabs/tab_strip.h"
 
 #if defined(OS_WIN)
 #include <windowsx.h>
 #endif
 
@@ skipping 1065 matching lines @@
     selection_model.Copy(original_selection);
   // Delete the existing DragController before creating a new one. We do this as
   // creating the DragController remembers the WebContents delegates and we need
   // to make sure the existing DragController isn't still a delegate.
   drag_controller_.reset();
   TabDragController::MoveBehavior move_behavior =
       TabDragController::REORDER;
   // Use MOVE_VISIBILE_TABS in the following conditions:
   // . Mouse event generated from touch and the left button is down (the right
   //   button corresponds to a long press, which we want to reorder).
-  // . Gesture begin and control key isn't down.
+  // . Gesture tap down and control key isn't down.
   // . Real mouse event and control is down. This is mostly for testing.
   DCHECK(event.type() == ui::ET_MOUSE_PRESSED ||
-         event.type() == ui::ET_GESTURE_BEGIN);
+         event.type() == ui::ET_GESTURE_TAP_DOWN);
   if (touch_layout_ &&
       ((event.type() == ui::ET_MOUSE_PRESSED &&
         (((event.flags() & ui::EF_FROM_TOUCH) &&
           static_cast<const ui::MouseEvent&>(event).IsLeftMouseButton()) ||
          (!(event.flags() & ui::EF_FROM_TOUCH) &&
           static_cast<const ui::MouseEvent&>(event).IsControlDown()))) ||
-       (event.type() == ui::ET_GESTURE_BEGIN && !event.IsControlDown()))) {
+       (event.type() == ui::ET_GESTURE_TAP_DOWN && !event.IsControlDown()))) {
     move_behavior = TabDragController::MOVE_VISIBILE_TABS;
   }
 
   drag_controller_.reset(new TabDragController);
   drag_controller_->Init(
       this, tab, tabs, gfx::Point(x, y), event.x(), selection_model,
       move_behavior, EventSourceFromEvent(event));
 }
 
 void TabStrip::ContinueDrag(views::View* view, const ui::LocatedEvent& event) {
@@ skipping 1532 matching lines @@
 
 void TabStrip::OnMouseEntered(const ui::MouseEvent& event) {
   SetResetToShrinkOnExit(true);
 }
 
 void TabStrip::OnGestureEvent(ui::GestureEvent* event) {
   SetResetToShrinkOnExit(false);
   switch (event->type()) {
     case ui::ET_GESTURE_SCROLL_END:
     case ui::ET_SCROLL_FLING_START:
-    case ui::ET_GESTURE_END:
       EndDrag(END_DRAG_COMPLETE);
       if (adjust_layout_) {
         SetStackedLayout(true);
         controller_->StackedLayoutMaybeChanged();
       }
       break;
 
     case ui::ET_GESTURE_LONG_PRESS:
       if (drag_controller_.get())
         drag_controller_->SetMoveBehavior(TabDragController::REORDER);
       break;
 
     case ui::ET_GESTURE_LONG_TAP: {
       EndDrag(END_DRAG_CANCEL);
       gfx::Point local_point = event->location();
       Tab* tab = FindTabForEvent(local_point);
       if (tab) {
         ConvertPointToScreen(this, &local_point);
         ShowContextMenuForTab(tab, local_point, ui::MENU_SOURCE_TOUCH);
       }
       break;
     }
 
     case ui::ET_GESTURE_SCROLL_UPDATE:
       ContinueDrag(this, *event);
       break;
 
-    case ui::ET_GESTURE_BEGIN:
-      EndDrag(END_DRAG_CANCEL);
-      break;
-
     case ui::ET_GESTURE_TAP: {
       const int active_index = controller_->GetActiveIndex();
       DCHECK_NE(-1, active_index);
       Tab* active_tab = tab_at(active_index);
       TouchUMA::GestureActionType action = TouchUMA::GESTURE_TABNOSWITCH_TAP;
-      if (active_tab->tab_activated_with_last_gesture_begin())
+      if (active_tab->tab_activated_with_last_tap_down())
         action = TouchUMA::GESTURE_TABSWITCH_TAP;
       TouchUMA::RecordGestureAction(action);
       break;
     }
 
     default:
       break;
   }
   event->SetHandled();
 }
@@ skipping 21 matching lines @@
           ConvertPointToViewAndGetEventHandler(this, newtab_button_, point);
       if (view)
         return view;
     }
     Tab* tab = FindTabForEvent(point);
     if (tab)
       return ConvertPointToViewAndGetEventHandler(this, tab, point);
   }
   return this;
 }