Removing unused roles(7) from blink.

Source/modules/accessibility/AXRenderObject.cpp

 /*
 * Copyright (C) 2008 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
@@ skipping 1753 matching lines @@
     // Find if a parent of this object should handle aria-expanded changes.
     AXObject* containerParent = this->parentObject();
     while (containerParent) {
         bool foundParent = false;
 
         switch (containerParent->roleValue()) {
         case TreeRole:
         case TreeGridRole:
         case GridRole:
         case TableRole:
-        case BrowserRole:
             foundParent = true;
             break;
         default:
             break;
         }
 
         if (foundParent)
             break;
 
         containerParent = containerParent->parentObject();
@@ skipping 672 matching lines @@
         if (label && label->renderer()) {
             LayoutRect labelRect = axObjectCache()->getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace blink