Simplify TouchAction enum to be a simple bit flag

third_party/WebKit/Source/core/input/TouchActionUtil.cpp

 // Copyright 2015 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 "config.h"
 #include "core/input/TouchActionUtil.h"
 
 #include "core/dom/Node.h"
 #include "core/layout/LayoutBox.h"
 #include "core/layout/LayoutObject.h"
@@ skipping 10 matching lines @@
 static bool supportsTouchAction(const LayoutObject& object)
 {
     if (object.isInline() && !object.isReplaced())
         return false;
     if (object.isTableRow() || object.isLayoutTableCol())
         return false;
 
     return true;
 }
 
-static TouchAction intersectTouchAction(TouchAction action1, TouchAction action2)
-{
-    if (action1 == TouchActionNone || action2 == TouchActionNone)
-        return TouchActionNone;
-    if (action1 == TouchActionAuto)
-        return action2;
-    if (action2 == TouchActionAuto)
-        return action1;
-    if (!(action1 & action2))
-        return TouchActionNone;
-    return action1 & action2;
-}
-
 } // namespace
 
 TouchAction computeEffectiveTouchAction(const Node& node)
 {
     // Start by permitting all actions, then walk the elements supporting
     // touch-action from the target node up to the nearest scrollable ancestor
     // and exclude any prohibited actions.
     TouchAction effectiveTouchAction = TouchActionAuto;
     for (const Node* curNode = &node; curNode; curNode = ComposedTreeTraversal::parent(*curNode)) {
         if (LayoutObject* layoutObject = curNode->layoutObject()) {
             if (supportsTouchAction(*layoutObject)) {
                 TouchAction action = layoutObject->style()->touchAction();
-                effectiveTouchAction = intersectTouchAction(action, effectiveTouchAction);
+                effectiveTouchAction &= action;
                 if (effectiveTouchAction == TouchActionNone)
                     break;
             }
 
             // If we've reached an ancestor that supports a touch action, search no further.
             if (layoutObject->isBox() && toLayoutBox(layoutObject)->scrollsOverflow())
                 break;
         }
     }
     return effectiveTouchAction;
 }
 
 } // namespace TouchActionUtil
 } // namespace blink