for 48250, turn off mouse capture when a drag gesture begins. r=mjudge.

content/events/src/nsEventStateManager.cpp

@@ -756,6 +756,9 @@ nsEventStateManager :: GenerateDragGesture ( nsIPresContext* aPresContext, nsGUI
       mCurrentTarget = mGestureDownFrame;
       nsCOMPtr<nsIContent> lastContent;
       if ( mGestureDownFrame ) {
+        // the mouseDown captures the mouse, make sure we release it so that dragging
+        // to other views works correctly.
+        mGestureDownFrame->CaptureMouse ( aPresContext, PR_FALSE );
         mGestureDownFrame->GetContentForEvent(aPresContext, aEvent, getter_AddRefs(lastContent));
         if ( lastContent )
           lastContent->HandleDOMEvent(aPresContext, &event, nsnull, NS_EVENT_FLAG_INIT, &status);

layout/events/src/nsEventStateManager.cpp

@@ -756,6 +756,9 @@ nsEventStateManager :: GenerateDragGesture ( nsIPresContext* aPresContext, nsGUI
       mCurrentTarget = mGestureDownFrame;
       nsCOMPtr<nsIContent> lastContent;
       if ( mGestureDownFrame ) {
+        // the mouseDown captures the mouse, make sure we release it so that dragging
+        // to other views works correctly.
+        mGestureDownFrame->CaptureMouse ( aPresContext, PR_FALSE );
         mGestureDownFrame->GetContentForEvent(aPresContext, aEvent, getter_AddRefs(lastContent));
         if ( lastContent )
           lastContent->HandleDOMEvent(aPresContext, &event, nsnull, NS_EVENT_FLAG_INIT, &status);