Track constant InputDeviceCapabilities objects per-window.

third_party/WebKit/Source/core/input/InputDeviceCapabilities.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 InputDeviceCapabilities_h
 #define InputDeviceCapabilities_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/CoreExport.h"
 #include "core/input/InputDeviceCapabilitiesInit.h"
 
 namespace blink {
 
 class CORE_EXPORT InputDeviceCapabilities final
     : public GarbageCollected<InputDeviceCapabilities>,
       public ScriptWrappable {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
-  // This return a static local InputDeviceCapabilities pointer which has
-  // firesTouchEvents set to be true.
-  static InputDeviceCapabilities* firesTouchEventsSourceCapabilities();
-
-  // This return a static local InputDeviceCapabilities pointer which has
-  // firesTouchEvents set to be false.
-  static InputDeviceCapabilities* doesntFireTouchEventsSourceCapabilities();
-
   static InputDeviceCapabilities* create(bool firesTouchEvents) {
     return new InputDeviceCapabilities(firesTouchEvents);
   }
 
   static InputDeviceCapabilities* create(
       const InputDeviceCapabilitiesInit& initializer) {
     return new InputDeviceCapabilities(initializer);
   }
 
   bool firesTouchEvents() const { return m_firesTouchEvents; }
 
   DEFINE_INLINE_TRACE() {}
 
  private:
   InputDeviceCapabilities(bool firesTouchEvents);
   InputDeviceCapabilities(const InputDeviceCapabilitiesInit&);
 
   // Whether this device dispatches touch events. This mainly lets developers
   // avoid handling both touch and mouse events dispatched for a single user
   // action.
   bool m_firesTouchEvents;
 };
 
+// Grouping constant-valued InputDeviceCapabilities objects together,
+// which is kept and used by each 'view' (DOMWindow) that dispatches
+// events parameterized over InputDeviceCapabilities.
+//
+// TODO(sof): lazily instantiate InputDeviceCapabilities instances upon
+// UIEvent access instead. This would allow internal tracking of such
+// capabilities by value.
+class InputDeviceCapabilitiesConstants final
+    : public GarbageCollected<InputDeviceCapabilitiesConstants> {
+ public:
+  // Returns an InputDeviceCapabilities which has
+  // |firesTouchEvents| set to value of |firesTouch|.
+  InputDeviceCapabilities* firesTouchEvents(bool firesTouch);
+
+  DEFINE_INLINE_TRACE() {
+    visitor->trace(m_firesTouchEvents);
+    visitor->trace(m_doesntFireTouchEvents);
+  }
+
+ private:
+  Member<InputDeviceCapabilities> m_firesTouchEvents;
+  Member<InputDeviceCapabilities> m_doesntFireTouchEvents;
+};
+
 }  // namespace blink
 
 #endif  // InputDeviceCapabilities_h