Update to handle absolute-looking paths in manifests and still produce nice-looking URLs.

chrome/common/extensions/extension.cc

 // Copyright (c) 2012 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.h"
 
 #include "base/base64.h"
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
@@ skipping 416 matching lines @@
   else
     return manifest_->type();
 }
 
 // static
 GURL Extension::GetResourceURL(const GURL& extension_url,
                                const std::string& relative_path) {
   DCHECK(extension_url.SchemeIs(chrome::kExtensionScheme));
   DCHECK_EQ("/", extension_url.path());
 
-  GURL ret_val = GURL(extension_url.spec() + relative_path);
+  std::string path = relative_path;
+
+  // If the relative path starts with "/", it is "absolute" relative to the
+  // extension base directory, but extension_url is already specified to refer
+  // to that base directory, so strip the leading "/" if present.
+  if (relative_path.size() > 0 && relative_path[0] == '/')
+    path = relative_path.substr(1);
+
+  GURL ret_val = GURL(extension_url.spec() + path);
   DCHECK(StartsWithASCII(ret_val.spec(), extension_url.spec(), false));
 
   return ret_val;
 }
 
 bool Extension::is_platform_app() const {
   return manifest_->is_platform_app();
 }
 
 bool Extension::is_hosted_app() const {
@@ skipping 3096 matching lines @@
     already_disabled(false),
     extension(extension) {}
 
 UpdatedExtensionPermissionsInfo::UpdatedExtensionPermissionsInfo(
     const Extension* extension,
     const ExtensionPermissionSet* permissions,
     Reason reason)
     : reason(reason),
       extension(extension),
       permissions(permissions) {}