Implement mimetype sniffing for extensions.

chrome/common/extensions/extension.h

 // Copyright (c) 2009 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.
 
 #ifndef CHROME_COMMON_EXTENSIONS_EXTENSION_H_
 #define CHROME_COMMON_EXTENSIONS_EXTENSION_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 46 matching lines @@
   // The name of the manifest inside an extension.
   static const char kManifestFilename[];
 
 #if defined(OS_WIN)
   static const char* kExtensionRegistryPath;
 #endif
 
   // The number of bytes in a legal id.
   static const size_t kIdSize;
 
+  // The mimetype used for extensions.
+  static const char kMimeType[];
+
   Extension() : location_(INVALID), is_theme_(false) {}
   explicit Extension(const FilePath& path);
   virtual ~Extension();
 
-  // Returns true if the specified file is an extension.
-  static bool IsExtension(const FilePath& file_name);
-
   // Resets the id counter. This is only useful for unit tests.
   static void ResetGeneratedIdCounter() {
     id_counter_ = 0;
   }
 
   // Checks to see if the extension has a valid ID.
   static bool IdIsValid(const std::string& id);
 
+  // Returns true if the specified file is an extension.
+  static bool IsExtension(const FilePath& file_name);
+
   // Whether the |location| is external or not.
   static inline bool IsExternalLocation(Location location) {
     return location == Extension::EXTERNAL_PREF ||
            location == Extension::EXTERNAL_REGISTRY;
   }
 
   // Returns an absolute url to a resource inside of an extension. The
   // |extension_url| argument should be the url() from an Extension object. The
   // |relative_path| can be untrusted user input. The returned URL will either
   // be invalid() or a child of |extension_url|.
@@ skipping 175 matching lines @@
 
   // URL for fetching an update manifest
   GURL update_url_;
 
   FRIEND_TEST(ExtensionTest, LoadPageActionHelper);
 
   DISALLOW_COPY_AND_ASSIGN(Extension);
 };
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_H_