Don't keep a separate m_revalidatingRequest on Resource

third_party/WebKit/Source/bindings/core/v8/ScriptStreamer.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 "bindings/core/v8/ScriptStreamer.h"
 
 #include "bindings/core/v8/ScriptStreamerThread.h"
 #include "bindings/core/v8/V8ScriptRunner.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
@@ skipping 635 matching lines @@
     ASSERT(scriptState->contextIsValid());
     ScriptResource* resource = script->resource();
     if (resource->isLoaded()) {
         recordNotStreamingReasonHistogram(scriptType, AlreadyLoaded);
         return false;
     }
     if (!resource->url().protocolIsInHTTPFamily()) {
         recordNotStreamingReasonHistogram(scriptType, NotHTTP);
         return false;
     }
-    if (resource->isCacheValidator()) {

[Nate Chapin, 2016/05/19 22:18:38]

I think this this was a cache for the old way of revalidating with a separate
resource. I can't find any tests that indicate it's still needed.

[yhirano, 2016/05/23 11:40:38]

It seems this branch was introduced at
https://codereview.chromium.org/368283002#msg11, but I still don't understand
why it was needed and why it isn't needed any more. I'll try again tomorrow.

[yhirano, 2016/05/24 11:18:51]

I think this branch is needed because ScriptResource doesn't call
notifyAppendData when the revalidation succeeds.

I couldn't find any layout tests testing ScriptStreamer specifically by the way
(I skimmed ScriptStream.cpp changes but none of them updated LayoutTests except
https://codereview.chromium.org/1807193003).

[Nate Chapin, 2016/05/26 21:43:02]

Ok, the lack of tests is annoying, but I agree that the lack of
notifyAppendData() calls is a plausible reason, so I'm reverting this block.
That may be something to think about if we refactor ResourceClient callbacks at
some point.

-        recordNotStreamingReasonHistogram(scriptType, Reload);
-        // This happens e.g., during reloads. We're actually not going to load
-        // the current Resource of the PendingScript but switch to another
-        // Resource -> don't stream.
-        return false;
-    }
     // We cannot filter out short scripts, even if we wait for the HTTP headers
     // to arrive: the Content-Length HTTP header is not sent for chunked
     // downloads.
 
     // Decide what kind of cached data we should produce while streaming. Only
     // produce parser cache if the non-streaming compile takes advantage of it.
     v8::ScriptCompiler::CompileOptions compileOption = v8::ScriptCompiler::kNoCompileOptions;
     if (settings->v8CacheOptions() == V8CacheOptionsParse)
         compileOption = v8::ScriptCompiler::kProduceParserCache;
 
     // The Resource might go out of scope if the script is no longer
     // needed. This makes PendingScript notify the ScriptStreamer when it is
     // destroyed.
     script->setStreamer(ScriptStreamer::create(script, scriptType, scriptState, compileOption, loadingTaskRunner));
 
     return true;
 }
 
 } // namespace blink