Improve mobile device rotation behavior.

Source/WebKit/chromium/src/ViewportAnchor.h

Index: Source/WebKit/chromium/src/ViewportAnchor.h
diff --git a/Source/WebKit/chromium/public/WebUserGestureToken.h b/Source/WebKit/chromium/src/ViewportAnchor.h
similarity index 55%
copy from Source/WebKit/chromium/public/WebUserGestureToken.h
copy to Source/WebKit/chromium/src/ViewportAnchor.h
index e81b6262b819b9fbbabb6659f94e648a9096105c..b3797e3a0317961cf4f426adec66982f8c1f8cce 100644
--- a/Source/WebKit/chromium/public/WebUserGestureToken.h
+++ b/Source/WebKit/chromium/src/ViewportAnchor.h
@@ -28,46 +28,53 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef WebUserGestureToken_h
-#define WebUserGestureToken_h
+#ifndef ViewportAnchor_h
+#define ViewportAnchor_h
 
-#include "../../../Platform/chromium/public/WebPrivatePtr.h"
+#include "FloatSize.h"
+#include "IntPoint.h"
+#include "IntRect.h"
+#include "LayoutRect.h"
+#include <wtf/RefCounted.h>
 
 namespace WebCore {
-class UserGestureToken;
+class EventHandler;
+class IntSize;
+class Node;
 }
 
 namespace WebKit {
 
-// A WebUserGestureToken allows for storing the user gesture state of the
-// currently active context and reinstantiating it later on to continue
-// processing the user gesture in case it was not consumed meanwhile.
-class WebUserGestureToken {
+// ViewportAnchor provides a way to anchor a viewport origin to a DOM node.
+// In particular, the user supplies the current viewport (in CSS coordinates)
+// and an anchor point (in view coordinates, e.g., (0, 0) == viewport origin,
+// (0.5, 0) == viewport top center). The anchor point tracks the underlying DOM
+// node; as the node moves or the view is resized, the viewport anchor maintains
+// its orientation relative to the node, and the viewport origin maintains its
+// orientation relative to the anchor.
+#if ENABLE(VIEWPORT)
+class ViewportAnchor {
+    WTF_MAKE_NONCOPYABLE(ViewportAnchor);
 public:
-    WebUserGestureToken() { }
-    WebUserGestureToken(const WebUserGestureToken& other) { assign(other); }
-    WebUserGestureToken& operator=(const WebUserGestureToken& other)
-    {
-        assign(other);
-        return *this;
-    }
-    ~WebUserGestureToken() { reset(); }
+    explicit ViewportAnchor(WebCore::EventHandler* eventHandler);
 
-    WEBKIT_EXPORT bool hasGestures() const;
-    bool isNull() const { return m_token.isNull(); }
+    void setAnchor(const WebCore::IntRect& viewRect, const WebCore::FloatSize& anchorInViewCoords);
 
-#if WEBKIT_IMPLEMENTATION
-    explicit WebUserGestureToken(PassRefPtr<WebCore::UserGestureToken>);
-    operator PassRefPtr<WebCore::UserGestureToken>() const;
-#endif
+    WebCore::IntPoint computeOrigin(const WebCore::IntSize& currentViewSize) const;
 
 private:
-    WEBKIT_EXPORT void assign(const WebUserGestureToken&);
-    WEBKIT_EXPORT void reset();
+    WebCore::EventHandler* m_eventHandler;
 
-    WebPrivatePtr<WebCore::UserGestureToken> m_token;
+    WebCore::IntRect m_viewRect;
+
+    RefPtr<WebCore::Node> m_anchorNode;
+    WebCore::LayoutRect m_anchorNodeBounds;
+
+    WebCore::FloatSize m_anchorInViewCoords;
+    WebCore::FloatSize m_anchorInNodeCoords;
 };
+#endif // ENABLE(VIEWPORT)
 
 } // namespace WebKit
 
-#endif // WebUserGestureToken_h
+ #endif