Do not reuse opaque Resource from a service worker for non no-cors requests

third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp

Index: third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
diff --git a/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp b/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
index dd07563a5e11cf9cc61916fcb27957720a7dd178..badae17cfeb94f84bc176855538b7f72685cdb07 100644
--- a/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
+++ b/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
@@ -693,6 +693,11 @@ ResourceFetcher::RevalidationPolicy ResourceFetcher::determineRevalidationPolicy
     if (request.downloadToFile() || request.useStreamOnResponse())
         return Reload;
 
+    // Never reuse opaque responses from a service worker for requests that
+    // are not no-cors. https://crbug.com/625575
+    if (existingResource->response().serviceWorkerResponseType() == WebServiceWorkerResponseTypeOpaque && request.fetchRequestMode() != WebURLRequest::FetchRequestModeNoCORS)

[horo, 2016/07/28 07:29:00]

I think we should also check
existingResource->response().wasFetchedViaServiceWorker().

[hiroshige, 2016/08/05 07:53:14]

Done.

+        return Reload;
+
     // If resource was populated from a SubstituteData load or data: url, use it.
     if (isStaticData)
         return Use;