Enable forced extension updates on NaCl arch mismatch.

extensions/common/extension.cc

Index: extensions/common/extension.cc
diff --git a/extensions/common/extension.cc b/extensions/common/extension.cc
index d8e798e516e2795c50f670fd27a6b26e4a1ed6e9..b4455a481cfb825cc7c68e1c07a881d7fdf93a22 100644
--- a/extensions/common/extension.cc
+++ b/extensions/common/extension.cc
@@ -435,6 +435,16 @@ void Extension::AddWebExtentPattern(const URLPattern& pattern) {
   extent_.AddPattern(pattern);
 }
 
+void Extension::SetPlatformSpecificResourceArchs(
+    const std::set<std::string>& archs) {
+  platform_specific_resource_archs_ = archs;
+}
+
+void Extension::GetPlatformSpecificResourceArchs(
+    std::set<std::string>* archs) const {
+  *archs = platform_specific_resource_archs_;
+}
+
 // static
 bool Extension::InitExtensionID(extensions::Manifest* manifest,
                                 const base::FilePath& path,