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

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

Index: third_party/WebKit/Source/WebKit/chromium/public/WebScrollbar.h
===================================================================
--- third_party/WebKit/Source/WebKit/chromium/public/WebScrollbar.h	(revision 92488)
+++ third_party/WebKit/Source/WebKit/chromium/public/WebScrollbar.h	(working copy)
@@ -34,9 +34,13 @@
 #include "WebCanvas.h"
 #include "WebCommon.h"
 
+// TODO(jam): take this out once Chrome rolls this revision of WebKit.
+#define WEBSCROLLBAR_SUPPORTS_OVERLAY
+
 namespace WebKit {
 
 class WebInputEvent;
+class WebPluginContainer;
 class WebScrollbarClient;
 struct WebRect;
 
@@ -59,14 +63,20 @@
         ScrollByPixel
     };
 
-    // Creates a WebScrollbar.
-    WEBKIT_EXPORT static WebScrollbar* create(WebScrollbarClient*, Orientation);
+    // Creates a WebScrollbar for use by a plugin. The plugin container and
+    // client are guaranteed to outlive this object.
+    WEBKIT_EXPORT static WebScrollbar* create(Orientation,

[darin (slow to review), 2011/08/10 18:00:34]

nit: Let's call this createForPlugin just to be a bit more self-documenting.

+                                              WebPluginContainer*,
+                                              WebScrollbarClient*);
 
     virtual ~WebScrollbar() {}
 
     // Gets the thickness of the scrollbar in pixels.
     WEBKIT_EXPORT static int defaultThickness();
 
+    // Return true if this is an overlay scrollbar.
+    virtual bool isOverlay() = 0;

[darin (slow to review), 2011/08/10 18:00:34]

can this be a const method?  (like value())

+
     // Sets the rectangle of the scrollbar.
     virtual void setLocation(const WebRect&) = 0;