Skip the Service Worker CORS fallback for same origin requests. [1/2 blink]

Source/core/loader/DocumentThreadableLoader.cpp

Index: Source/core/loader/DocumentThreadableLoader.cpp
diff --git a/Source/core/loader/DocumentThreadableLoader.cpp b/Source/core/loader/DocumentThreadableLoader.cpp
index 8b84b7147cada891d7ace3393be6bb007a543489..2516ff941788ef145fc92e332eda17a3f1fe2017 100644
--- a/Source/core/loader/DocumentThreadableLoader.cpp
+++ b/Source/core/loader/DocumentThreadableLoader.cpp
@@ -452,7 +452,17 @@ void DocumentThreadableLoader::handleResponse(unsigned long identifier, const Re
         return;
     }
 
-    ASSERT(!m_fallbackRequestForServiceWorker);
+    // Even if the request met the conditions to get handled by a Service Worker
+    // in the constructor of this class (and therefore
+    // |m_fallbackRequestForServiceWorker| is set), the Service Worker may skip
+    // processing the request. Only if the request is same origin, the skipped
+    // response may come here (wasFetchedViaServiceWorker() returns false) since
+    // such a request doesn't have to go through the CORS algorithm by calling
+    // loadFallbackRequestForServiceWorker().
+    // FIXME: We should use |m_sameOriginRequest| when we will support
+    // Suborigins for Service Worker.

[falken, 2015/07/22 22:05:56]

Can you link to a bug or make it more clear to future readers when the FIXME can
be addressed? I'm unfamiliar with Suborigins for Service Worker (and I work on
SW). 

[horo, 2015/07/23 03:33:56]

Done.

+    ASSERT(!m_fallbackRequestForServiceWorker || securityOrigin()->canRequest(m_fallbackRequestForServiceWorker->url()));
+    m_fallbackRequestForServiceWorker = nullptr;
 
     if (!m_sameOriginRequest && m_options.crossOriginRequestPolicy == UseAccessControl) {
         String accessControlErrorDescription;