Delay instantiating InputDeviceCapabilities until accessed.

third_party/WebKit/Source/core/page/FocusController.h

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef FocusController_h
 #define FocusController_h
 
 #include "core/CoreExport.h"
+#include "core/input/InputDeviceCapabilities.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebFocusType.h"
 #include "wtf/Forward.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
 struct FocusCandidate;
 struct FocusParams;
 class Document;
 class Element;
 class FocusChangedObserver;
 class Frame;
 class HTMLFrameOwnerElement;
-class InputDeviceCapabilities;
 class LocalFrame;
 class Node;
 class Page;
 class RemoteFrame;
 
 class CORE_EXPORT FocusController final
     : public GarbageCollected<FocusController> {
   WTF_MAKE_NONCOPYABLE(FocusController);
 
  public:
   static FocusController* create(Page*);
 
   void setFocusedFrame(Frame*, bool notifyEmbedder = true);
   void focusDocumentView(Frame*, bool notifyEmbedder = true);
   LocalFrame* focusedFrame() const;
   Frame* focusedOrMainFrame() const;
 
   // Finds the focused HTMLFrameOwnerElement, if any, in the provided frame.
   // An HTMLFrameOwnerElement is considered focused if the frame it owns, or
   // one of its descendant frames, is currently focused.
   HTMLFrameOwnerElement* focusedFrameOwnerElement(
       LocalFrame& currentFrame) const;
 
   // Determines whether the provided Document has focus according to
   // http://www.w3.org/TR/html5/editing.html#dom-document-hasfocus
   bool isDocumentFocused(const Document&) const;
 
   bool setInitialFocus(WebFocusType);
   bool advanceFocus(WebFocusType type,
-                    InputDeviceCapabilities* sourceCapabilities = nullptr) {
+                    const InputDeviceCapabilitiesValue& sourceCapabilities =
+                        InputDeviceCapabilitiesValue()) {
     return advanceFocus(type, false, sourceCapabilities);
   }
   bool advanceFocusAcrossFrames(
       WebFocusType,
       RemoteFrame* from,
       LocalFrame* to,
-      InputDeviceCapabilities* sourceCapabilities = nullptr);
+      const InputDeviceCapabilitiesValue& sourceCapabilities);
   Element* findFocusableElementInShadowHost(const Element& shadowHost);
 
   bool setFocusedElement(Element*, Frame*, const FocusParams&);
   // |setFocusedElement| variant with SelectionBehaviorOnFocus::None,
   // |WebFocusTypeNone, and null InputDeviceCapabilities.
   bool setFocusedElement(Element*, Frame*);
 
   void setActive(bool);
   bool isActive() const { return m_isActive; }
 
   void setFocused(bool);
   bool isFocused() const { return m_isFocused; }
 
   void registerFocusChangedObserver(FocusChangedObserver*);
 
   DECLARE_TRACE();
 
  private:
   explicit FocusController(Page*);
 
   Element* findFocusableElement(WebFocusType, Element&);
 
   bool advanceFocus(WebFocusType,
                     bool initialFocus,
-                    InputDeviceCapabilities* sourceCapabilities = nullptr);
+                    const InputDeviceCapabilitiesValue&);
   bool advanceFocusDirectionally(WebFocusType);
   bool advanceFocusInDocumentOrder(LocalFrame*,
                                    Element* start,
                                    WebFocusType,
                                    bool initialFocus,
-                                   InputDeviceCapabilities* sourceCapabilities);
+                                   const InputDeviceCapabilitiesValue&);
 
   bool advanceFocusDirectionallyInContainer(Node* container,
                                             const LayoutRect& startingRect,
                                             WebFocusType);
   void findFocusCandidateInContainer(Node& container,
                                      const LayoutRect& startingRect,
                                      WebFocusType,
                                      FocusCandidate& closest);
 
   void notifyFocusChangedObservers() const;
 
   Member<Page> m_page;
   Member<Frame> m_focusedFrame;
   bool m_isActive;
   bool m_isFocused;
   bool m_isChangingFocusedFrame;
   HeapHashSet<WeakMember<FocusChangedObserver>> m_focusChangedObservers;
 };
 
 }  // namespace blink
 
 #endif  // FocusController_h