[Fetch] Add a deprecation warning for Request.context

Source/modules/fetch/Request.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "modules/fetch/Request.h"
 
 #include "bindings/core/v8/Dictionary.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/fetch/FetchUtils.h"
 #include "core/fetch/ResourceLoaderOptions.h"
+#include "core/inspector/ConsoleMessage.h"
 #include "core/loader/ThreadableLoader.h"
 #include "modules/fetch/BodyStreamBuffer.h"
 #include "modules/fetch/FetchBlobDataConsumerHandle.h"
 #include "modules/fetch/FetchManager.h"
 #include "modules/fetch/RequestInit.h"
 #include "platform/network/HTTPParsers.h"
 #include "platform/network/ResourceRequest.h"
 #include "platform/weborigin/Referrer.h"
 #include "public/platform/WebServiceWorkerRequest.h"
 #include "public/platform/WebURLRequest.h"
@@ skipping 311 matching lines @@
     // The url attribute's getter must return request's url, serialized with the exclude fragment flag set.
     if (!m_request->url().hasFragmentIdentifier())
         return m_request->url();
     KURL url(m_request->url());
     url.removeFragmentIdentifier();
     return url;
 }
 
 String Request::context() const
 {
+    executionContext()->addConsoleMessage(ConsoleMessage::create(DeprecationMessageSource, WarningMessageLevel, "Request.context is deprecated and will be removed in M46."));

[falken, 2015/08/13 11:37:19]

Deprecation messages are usually added to UseCounter.cpp:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

[hiroshige, 2015/08/13 11:39:10]

Hmm, so we should add a new use counter and corresponding deprecation message,
right?

[falken, 2015/08/13 11:45:11]

I think that's the convention, that's what I did for Client.postMessage:
https://codereview.chromium.org/925293002

This also means the author doesn't get spammed with deprecation warnings if they
use the feature multiple times in a page.

[hiroshige, 2015/08/13 12:01:23]

Done.

+
     // "The context attribute's getter must return request's context"
     switch (m_request->context()) {
     case WebURLRequest::RequestContextUnspecified:
         return "";
     case WebURLRequest::RequestContextAudio:
         return "audio";
     case WebURLRequest::RequestContextBeacon:
         return "beacon";
     case WebURLRequest::RequestContextCSPReport:
         return "cspreport";
@@ skipping 173 matching lines @@
 }
 
 DEFINE_TRACE(Request)
 {
     Body::trace(visitor);
     visitor->trace(m_request);
     visitor->trace(m_headers);
 }
 
 } // namespace blink