Adds a feature to MHTML serialization that omits subframes and subresources marked no-store.

third_party/WebKit/Source/core/frame/FrameSerializer.h

Index: third_party/WebKit/Source/core/frame/FrameSerializer.h
diff --git a/third_party/WebKit/Source/core/frame/FrameSerializer.h b/third_party/WebKit/Source/core/frame/FrameSerializer.h
index 9aaf155303aa327a2b38ecb37bc3f76ff5d6ceef..51092090b801b19df05361a71f22a9dd3f439629 100644
--- a/third_party/WebKit/Source/core/frame/FrameSerializer.h
+++ b/third_party/WebKit/Source/core/frame/FrameSerializer.h
@@ -85,9 +85,15 @@ public:
             return false;
         }
 
-        // Tells whether to skip serialization of a subresource with a given URI.
-        // Used to deduplicate resources across multiple frames.
-        virtual bool shouldSkipResource(const KURL&)
+        // Tells whether to skip serialization of a subresource or CSSStyleSheet
+        // with a given URI. Used to deduplicate resources across multiple frames.
+        virtual bool shouldSkipURL(const KURL&)

[Dmitry Titov, 2016/05/17 22:47:10]

ShouldSkipResourceWithURL is probably more clear.

[dewittj, 2016/05/17 23:43:27]

Done.

+        {
+            return false;
+        }
+
+        // Tells whether to skip serialization of a subresource.
+        virtual bool shouldSkipResource(Resource*)
         {
             return false;
         }