Allowing registering arbitrary schemes as supporting the fetch API.

Source/modules/fetch/FetchManager.cpp

Index: Source/modules/fetch/FetchManager.cpp
diff --git a/Source/modules/fetch/FetchManager.cpp b/Source/modules/fetch/FetchManager.cpp
index 3bc85626789af65ff5d3f21a72cbd496518ea0c4..dcc1c1afd8301f59f7a5caad2688d6a20faa68ec 100644
--- a/Source/modules/fetch/FetchManager.cpp
+++ b/Source/modules/fetch/FetchManager.cpp
@@ -34,6 +34,7 @@
 #include "platform/network/ResourceError.h"
 #include "platform/network/ResourceRequest.h"
 #include "platform/network/ResourceResponse.h"
+#include "platform/weborigin/SchemeRegistry.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "public/platform/WebURLRequest.h"
 #include "wtf/HashSet.h"
@@ -440,7 +441,7 @@ void FetchManager::Loader::performBasicFetch()
 {
     // "To perform a basic fetch using |request|, switch on |request|'s url's
     // scheme, and run the associated steps:"
-    if (m_request->url().protocolIsInHTTPFamily()) {
+    if (SchemeRegistry::shouldTreatURLSchemeAsSupportingFetchAPI(m_request->url().protocol())) {

[pdr., 2015/08/25 21:25:09]

This code is in the critical path but has to wait for a mutex. Is that
acceptable perf-wise?

[not at google - send to devlin, 2015/08/25 22:04:45]

(I will defer to fetch owner to answer this)

[tyoshino (SeeGerritForStatus), 2015/08/26 07:24:48]

We already have one in DocumentThreadableLoader. As we visit here only once for
each fetch(), it should be acceptable.

Ideally, this kind of registry should be initialized and frozen like ones in
src/url/url_util.cc (has just DCHECK on standard_schemes_locked). I'm not sure
we can do it on Blink.

         // "Return the result of performing an HTTP fetch using |request|."
         performHTTPFetch(false, false);
     } else {
@@ -456,7 +457,7 @@ void FetchManager::Loader::performNetworkError(const String& message)
 
 void FetchManager::Loader::performHTTPFetch(bool corsFlag, bool corsPreflightFlag)
 {
-    ASSERT(m_request->url().protocolIsInHTTPFamily());
+    ASSERT(SchemeRegistry::shouldTreatURLSchemeAsSupportingFetchAPI(m_request->url().protocol()));
     // CORS preflight fetch procedure is implemented inside DocumentThreadableLoader.
 
     // "1. Let |HTTPRequest| be a copy of |request|, except that |HTTPRequest|'s