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

chrome/browser/ui/views/tabs/tab.h

Index: chrome/browser/ui/views/tabs/tab.h
diff --git a/chrome/browser/ui/views/tabs/tab.h b/chrome/browser/ui/views/tabs/tab.h
index f4a67aa232b03dcd1a5e47998443740be7ef4da2..5dd1da83b099204cf8398e54429ffbd73d7ad280 100644
--- a/chrome/browser/ui/views/tabs/tab.h
+++ b/chrome/browser/ui/views/tabs/tab.h
@@ -96,11 +96,11 @@ class Tab : public gfx::AnimationDelegate,
   }
 
   // Returns true if this tab became the active tab selected in
-  // response to the last ui::ET_GESTURE_BEGIN gesture dispatched to
+  // response to the last ui::ET_GESTURE_TAP_DOWN gesture dispatched to
   // this tab. Only used for collecting UMA metrics.
   // See ash/touch/touch_uma.cc.
-  bool tab_activated_with_last_gesture_begin() const {
-    return tab_activated_with_last_gesture_begin_;
+  bool tab_activated_with_last_tap_down() const {
+    return tab_activated_with_last_tap_down_;
   }
 
   views::GlowHoverController* hover_controller() {
@@ -145,6 +145,10 @@ class Tab : public gfx::AnimationDelegate,
   FRIEND_TEST_ALL_PREFIXES(TabStripTest, TabHitTestMaskWhenStacked);
   FRIEND_TEST_ALL_PREFIXES(TabStripTest, ClippedTabCloseButton);
 
+  friend class TabDragController;
+  friend class TabDragControllerTest;
+  FRIEND_TEST_ALL_PREFIXES(TabDragControllerTest, DragWithGesture);
+
   // The animation object used to swap the favicon with the sad tab icon.
   class FaviconCrashAnimation;
   class TabCloseButton;
@@ -345,7 +349,7 @@ class Tab : public gfx::AnimationDelegate,
   views::ImageButton* close_button_;
   views::Label* title_;
 
-  bool tab_activated_with_last_gesture_begin_;
+  bool tab_activated_with_last_tap_down_;
 
   views::GlowHoverController hover_controller_;