Switch Sky to pointer events

sky/engine/core/frame/NewEventHandler.h

 // 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.
 
 #ifndef SKY_ENGINE_CORE_FRAME_NEWEVENTHANDLER_H_
 #define SKY_ENGINE_CORE_FRAME_NEWEVENTHANDLER_H_
 
+#include <map>
 #include "sky/engine/core/dom/Node.h"
 #include "sky/engine/core/rendering/HitTestRequest.h"
 #include "sky/engine/core/rendering/HitTestResult.h"
 #include "sky/engine/wtf/HashMap.h"
 
 namespace blink {
 
 class LocalFrame;
 class WebPointerEvent;
 
@@ skipping 11 matching lines @@
     bool handlePointerMoveEvent(const WebPointerEvent&);
     bool handlePointerCancelEvent(const WebPointerEvent&);
 
     bool dispatchPointerEvent(Node& target, const WebPointerEvent&);
     bool dispatchClickEvent(Node& capturingTarget, const WebPointerEvent&);
 
     Node* targetForHitTestResult(const HitTestResult& hitTestResult);
     HitTestResult performHitTest(const LayoutPoint&);
     void updateSelectionForPointerDown(const HitTestResult&, const WebPointerEvent&);
 
-    typedef HashMap<int, RefPtr<Node>> PointerTargetMap;
+    typedef std::map<int, RefPtr<Node>> PointerTargetMap;

[ojan, 2015/01/23 10:23:55]

Why didn't HashMap work? stl containers are terribad, no?

[abarth-chromium, 2015/01/23 16:51:33]

I kept having trouble with HashMap asserting in checkKey.  HashMap steals some
of the key values to mean special things (e.g., 0 and -1).  I tried some of the
other traits, but I failed to find something that worked.

In reality, the number of entries in this map are equal to the number of fingers
(or mice) that are down at once.  In practice, that's like one or two.  We could
use an array instead, which would probably be slightly more efficient.

 
     LocalFrame& m_frame;
     PointerTargetMap m_targetForPointer;
 };
 
 }
 
 #endif // SKY_ENGINE_CORE_FRAME_NEWEVENTHANDLER_H_