Pepper and WebKit API change to support a plugin knowing if a scrollbar is an overlay one.

third_party/WebKit/Source/WebKit/chromium/public/WebScrollbarGroup.h

+/*
+ * Copyright (C) 2011 Google 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:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * 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.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "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 THE COPYRIGHT
+ * OWNER 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 WebScrollbarGroup_h
+#define WebScrollbarGroup_h
+
+#include "WebCommon.h"
+
+namespace WebKit {
+
+// This allows binding the vertical and horizontal scrollbars that are associated
+// with the same area. This is necessary because on some platforms, the look and
+// feel of one scrollbar might depend on the other.
+class WebScrollbarGroup {
+public:
+    // Creates a WebScrollbarGroup.
+    WEBKIT_EXPORT static WebScrollbarGroup* create();
+
+    virtual ~WebScrollbarGroup() {}
+
+    // These all match the ScrollAnimator methods.
+    virtual void mouseEnteredContentArea() = 0;
+    virtual void mouseMovedInContentArea() = 0;
+    virtual void mouseExitedContentArea() = 0;
+    virtual void willStartLiveResize() = 0;
+    virtual void contentResized() = 0;
+    virtual void willEndLiveResize() = 0;
+};
+
+} // namespace WebKit
+
+#endif