Use per-frame TaskRunner instead of thread's default in DataConsumerHandle

content/child/web_data_consumer_handle_impl.h

 // 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.
 
 #ifndef CONTENT_CHILD_WEB_DATA_CONSUMER_HANDLE_IMPL_H_
 #define CONTENT_CHILD_WEB_DATA_CONSUMER_HANDLE_IMPL_H_
 
 #include <stddef.h>
 
 #include <memory>
 
+#include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "mojo/public/cpp/system/data_pipe.h"
 #include "mojo/public/cpp/system/watcher.h"
 #include "third_party/WebKit/public/platform/WebDataConsumerHandle.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace content {
 
 class CONTENT_EXPORT WebDataConsumerHandleImpl final
     : public NON_EXPORTED_BASE(blink::WebDataConsumerHandle) {
   typedef mojo::ScopedDataPipeConsumerHandle Handle;
   class Context;
 
  public:
   class CONTENT_EXPORT ReaderImpl final : public NON_EXPORTED_BASE(Reader) {
    public:
-    ReaderImpl(scoped_refptr<Context> context, Client* client);
+    ReaderImpl(scoped_refptr<Context> context, Client* client,
+               scoped_refptr<base::SingleThreadTaskRunner> task_runner);
     ~ReaderImpl() override;
     Result read(void* data,
                 size_t size,
                 Flags flags,
                 size_t* readSize) override;
     Result beginRead(const void** buffer,
                      Flags flags,
                      size_t* available) override;
     Result endRead(size_t readSize) override;
 
    private:
     Result HandleReadResult(MojoResult);
     void StartWatching();
     void OnHandleGotReadable(MojoResult);
 
     scoped_refptr<Context> context_;
     mojo::Watcher handle_watcher_;
     Client* client_;
   };
-  std::unique_ptr<Reader> obtainReader(Client* client) override;
+  std::unique_ptr<Reader> obtainReader(
+      Client* client,
+      std::unique_ptr<blink::WebTaskRunner> readerTaskRunner) override;
 
   explicit WebDataConsumerHandleImpl(Handle handle);
   ~WebDataConsumerHandleImpl() override;
 
  private:
   const char* debugName() const override;
 
   scoped_refptr<Context> context_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_WEB_DATA_CONSUMER_HANDLE_IMPL_H_