Handle online and offline redirects via interceptor and offline scheme

third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp

Index: third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp
diff --git a/third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp b/third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp
index 8f6f23fb22dae8f515f4fe91efbfadb0d66257d2..bb872a486d9e23a2d17ab906acf326688b459297 100644
--- a/third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp
+++ b/third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp
@@ -69,8 +69,8 @@ MHTMLArchive::MHTMLArchive()
 
 MHTMLArchive* MHTMLArchive::create(const KURL& url, SharedBuffer* data)
 {
-    // For security reasons we only load MHTML pages from local URLs.
-    if (!SchemeRegistry::shouldTreatURLSchemeAsLocal(url.protocol()))
+    // For security reasons we only load MHTML pages from local URLs or offline resource.
+    if (!SchemeRegistry::shouldTreatURLSchemeAsLocal(url.protocol()) && url.protocol() != "offline")
         return nullptr;
 
     MHTMLParser parser(data);