Move CrxFile, FileReader, ExtensionResource to src/extensions.

extensions/common/extension_resource.cc

Index: extensions/common/extension_resource.cc
diff --git a/chrome/common/extensions/extension_resource.cc b/extensions/common/extension_resource.cc
similarity index 97%
rename from chrome/common/extensions/extension_resource.cc
rename to extensions/common/extension_resource.cc
index eded1ac2e0d07d6fc9e7560d5dc121927b52335c..5a70539cce60483882390e91ec467bfd72870a32 100644
--- a/chrome/common/extensions/extension_resource.cc
+++ b/extensions/common/extension_resource.cc
@@ -2,12 +2,14 @@
 // 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_resource.h"
+#include "extensions/common/extension_resource.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/threading/thread_restrictions.h"
 
+namespace extensions {
+
 ExtensionResource::ExtensionResource() : follow_symlinks_anywhere_(false) {
 }
 
@@ -120,3 +122,5 @@ bool ExtensionResource::ComparePathWithDefault(
     return false;
   }
 }
+
+}  // namespace extensions