Re-implement app overlap detection with new extent syntax.

chrome/common/extensions/extension_extent.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/extensions/extension_extent.h"
 
 bool ExtensionExtent::ContainsURL(const GURL& url) const {
   for (PatternList::const_iterator pattern = patterns_.begin();
        pattern != patterns_.end(); ++pattern) {
     if (pattern->MatchesUrl(url))
       return true;
   }
 
   return false;
 }
+
+bool ExtensionExtent::OverlapsWith(const ExtensionExtent& other) const {
+  // Two extension extents overlap if there is any one URL that would match at
+  // least one pattern in each of the extents.
+  for (PatternList::const_iterator i = patterns_.begin();
+       i != patterns_.end(); ++i) {
+    for (PatternList::const_iterator j = other.patterns().begin();
+         j != other.patterns().end(); ++j) {
+      if (i->OverlapsWith(*j))
+        return true;
+    }
+  }
+
+  return false;
+}