PlzNavigate: make MHTML iframe load working.

third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp

Index: third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp
diff --git a/third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp b/third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp
index 0554a74ba34eafad9c243add53a20c9f6df3ee9f..b8d199639b6a58cf78e66f43c9da3eafb911df46 100644
--- a/third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp
+++ b/third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp
@@ -413,7 +413,7 @@ Resource* ResourceFetcher::ResourceForStaticData(
   } else {
     ArchiveResource* archive_resource =
         archive_->SubresourceForURL(params.Url());
-    // Fall back to the network if the archive doesn't contain the resource.
+    // The archive doesn't contain the resource, the request must be aborted.
     if (!archive_resource)
       return nullptr;
     data = archive_resource->Data();
@@ -578,13 +578,19 @@ Resource* ResourceFetcher::RequestResource(
                                     params.Options().initiator_info.name);
   }
 
+  // An URL with the "cid" scheme can only be handled by an MHTML Archive.
+  // Abort the request when there is none.
+  if (resource_request.Url().ProtocolIs(kContentIdScheme) && !archive_) {

[pfeldman, 2017/05/05 20:45:36]

[perf]: check !archive_ first
[style nit]: drop {}

+    return nullptr;
+  }
+
   bool is_data_url = resource_request.Url().ProtocolIsData();
   bool is_static_data = is_data_url || substitute_data.IsValid() || archive_;
   if (is_static_data) {
     resource = ResourceForStaticData(params, factory, substitute_data);
     // Abort the request if the archive doesn't contain the resource, except in
     // the case of data URLs which might have resources such as fonts that need
-    // to be decoded only on demand.  These data URLs are allowed to be
+    // to be decoded only on demand. These data URLs are allowed to be
     // processed using the normal ResourceFetcher machinery.
     if (!resource && !is_data_url && archive_)
       return nullptr;