Revert 187230

> Implement the Stream registry in content
> 
> This is the first part of the content side of the Streams api.
> See:
> https://bugs.webkit.org/show_bug.cgi?id=110194
> https://dvcs.w3.org/hg/streams-api/raw-file/tip/Overview.htm
> 
> BUG=171585
> 
> 
> Review URL: https://chromiumcodereview.appspot.com/12335087

TBR=zork@chromium.org
Review URL: https://codereview.chromium.org/12611018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@187274 0039d316-1c4b-4281-b951-d872f2087c98

9 files changed, 0 insertions, 659 deletions

diff --git a/content/browser/streams/stream.cc b/content/browser/streams/stream.cc
deleted file mode 100644
index 0efec13..0000000
--- a/content/browser/streams/stream.cc
+++ /dev/null
@@ -1,113 +0,0 @@
-// Copyright (c) 2013 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 "content/browser/streams/stream.h"
-
-#include "base/bind.h"
-#include "base/message_loop_proxy.h"
-#include "content/browser/streams/stream_read_observer.h"
-#include "content/browser/streams/stream_registry.h"
-#include "content/browser/streams/stream_write_observer.h"
-#include "net/base/io_buffer.h"
-
-namespace {
-// Start throttling the connection at about 1MB.
-const size_t kDeferSizeThreshold = 40 * 32768;
-}
-
-namespace content {
-
-Stream::Stream(StreamRegistry* registry,
-               StreamWriteObserver* write_observer,
-               const GURL& security_origin,
-               const GURL& url)
-    : bytes_read_(0),
-      can_add_data_(true),
-      security_origin_(security_origin),
-      url_(url),
-      data_length_(0),
-      registry_(registry),
-      read_observer_(NULL),
-      write_observer_(write_observer) {
-  CreateByteStream(base::MessageLoopProxy::current(),
-                   base::MessageLoopProxy::current(),
-                   kDeferSizeThreshold,
-                   &writer_,
-                   &reader_);
-
-  // Setup callback for writing.
-  writer_->RegisterCallback(base::Bind(&Stream::OnSpaceAvailable, this));
-  reader_->RegisterCallback(base::Bind(&Stream::OnDataAvailable, this));
-
-  registry_->RegisterStream(this);
-}
-
-Stream::~Stream() {
-}
-
-bool Stream::SetReadObserver(StreamReadObserver* observer) {
-  if (read_observer_)
-    return false;
-  read_observer_ = observer;
-  return true;
-}
-
-void Stream::RemoveReadObserver(StreamReadObserver* observer) {
-  DCHECK(observer == read_observer_);
-  read_observer_ = NULL;
-}
-
-void Stream::AddData(scoped_refptr<net::IOBuffer> buffer, size_t size) {
-  can_add_data_ = writer_->Write(buffer, size);
-}
-
-void Stream::Finalize() {
-  writer_->Close(DOWNLOAD_INTERRUPT_REASON_NONE);
-  writer_.reset(NULL);
-
-  OnDataAvailable();
-}
-
-Stream::StreamState Stream::ReadRawData(net::IOBuffer* buf,
-                                        int buf_size,
-                                        int* bytes_read) {
-  if (!data_) {
-    data_length_ = 0;
-    bytes_read_ = 0;
-    ByteStreamReader::StreamState state = reader_->Read(&data_, &data_length_);
-    switch (state) {
-      case ByteStreamReader::STREAM_HAS_DATA:
-        break;
-      case ByteStreamReader::STREAM_COMPLETE:
-        registry_->UnregisterStream(url());
-        return STREAM_COMPLETE;
-      case ByteStreamReader::STREAM_EMPTY:
-        return STREAM_EMPTY;
-    }
-  }
-
-  size_t remaining_bytes = data_length_ - bytes_read_;
-  size_t to_read =
-      static_cast<size_t>(buf_size) < remaining_bytes ?
-      buf_size : remaining_bytes;
-  memcpy(buf->data(), data_->data() + bytes_read_, to_read);
-  bytes_read_ += to_read;
-  if (bytes_read_ >= data_length_)
-    data_ = NULL;
-
-  *bytes_read = to_read;
-  return STREAM_HAS_DATA;
-}
-
-void Stream::OnSpaceAvailable() {
-  can_add_data_ = true;
-  write_observer_->OnSpaceAvailable(this);
-}
-
-void Stream::OnDataAvailable() {
-  read_observer_->OnDataAvailable(this);
-}
-
-}  // namespace content
-
diff --git a/content/browser/streams/stream.h b/content/browser/streams/stream.h
deleted file mode 100644
index 567b10b..0000000
--- a/content/browser/streams/stream.h
+++ /dev/null
@@ -1,99 +0,0 @@
-// Copyright (c) 2013 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_BROWSER_STREAMS_STREAM_H_
-#define CONTENT_BROWSER_STREAMS_STREAM_H_
-
-#include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
-#include "content/browser/download/byte_stream.h"
-#include "content/common/content_export.h"
-#include "googleurl/src/gurl.h"
-
-namespace net {
-class IOBuffer;
-}
-
-namespace content {
-
-class StreamReadObserver;
-class StreamRegistry;
-class StreamWriteObserver;
-
-// A stream that sends data from an arbitrary source to an internal URL
-// that can be read by an internal consumer.  It will continue to pull from the
-// original URL as long as there is data available.  It can be read from
-// multiple clients, but only one can be reading at a time. This allows a
-// reader to consume part of the stream, then pass it along to another client
-// to continue processing the stream.
-class CONTENT_EXPORT Stream : public base::RefCountedThreadSafe<Stream> {
- public:
-  enum StreamState {
-    STREAM_HAS_DATA,
-    STREAM_COMPLETE,
-    STREAM_EMPTY,
-  };
-
-  // Creates a stream useable from the |security_origin|.
-  Stream(StreamRegistry* registry,
-         StreamWriteObserver* write_observer,
-         const GURL& security_origin,
-         const GURL& url);
-
-  // Sets the reader of this stream. Returns true on success, or false if there
-  // is already a reader.
-  bool SetReadObserver(StreamReadObserver* observer);
-
-  // Removes the read observer.  |observer| must be the current observer.
-  void RemoveReadObserver(StreamReadObserver* observer);
-
-  // Adds the data in |buffer| to the stream.  Takes ownership of |buffer|.
-  void AddData(scoped_refptr<net::IOBuffer> buffer, size_t size);
-
-  // Notifies this stream that it will not be receiving any more data.
-  void Finalize();
-
-  // Reads a maximum of |buf_size| from the stream into |buf|.  Sets
-  // |*bytes_read| to the number of bytes actually read.
-  // Returns STREAM_HAS_DATA if data was read, STREAM_EMPTY if no data was read,
-  // and STREAM_COMPLETE if the stream is finalized and all data has been read.
-  StreamState ReadRawData(net::IOBuffer* buf, int buf_size, int* bytes_read);
-
-  // Indicates whether there is space in the buffer to add more data.
-  bool can_add_data() const { return can_add_data_; }
-
-  const GURL& url() const { return url_; }
-
-  const GURL& security_origin() const { return security_origin_; }
-
- private:
-  friend class base::RefCountedThreadSafe<Stream>;
-
-  virtual ~Stream();
-
-  void OnSpaceAvailable();
-  void OnDataAvailable();
-
-  size_t bytes_read_;
-  bool can_add_data_;
-
-  GURL security_origin_;
-  GURL url_;
-
-  scoped_refptr<net::IOBuffer> data_;
-  size_t data_length_;
-
-  scoped_ptr<ByteStreamWriter> writer_;
-  scoped_ptr<ByteStreamReader> reader_;
-
-  StreamRegistry* registry_;
-  StreamReadObserver* read_observer_;
-  StreamWriteObserver* write_observer_;
-
-  DISALLOW_COPY_AND_ASSIGN(Stream);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_STREAMS_STREAM_H_
diff --git a/content/browser/streams/stream_context.cc b/content/browser/streams/stream_context.cc
deleted file mode 100644
index ca77df1..0000000
--- a/content/browser/streams/stream_context.cc
+++ /dev/null
@@ -1,44 +0,0 @@
-// Copyright (c) 2013 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 "content/browser/streams/stream_context.h"
-
-#include "base/bind.h"
-#include "content/browser/streams/stream_registry.h"
-#include "content/public/browser/browser_context.h"
-
-using base::UserDataAdapter;
-
-namespace {
-const char* kStreamContextKeyName = "content_stream_context";
-}
-
-namespace content {
-
-StreamContext::StreamContext() {}
-
-StreamContext* StreamContext::GetFor(BrowserContext* context) {
-  if (!context->GetUserData(kStreamContextKeyName)) {
-    scoped_refptr<StreamContext> stream = new StreamContext();
-    context->SetUserData(kStreamContextKeyName,
-                         new UserDataAdapter<StreamContext>(stream));
-    // Check first to avoid memory leak in unittests.
-    if (BrowserThread::IsMessageLoopValid(BrowserThread::IO)) {
-      BrowserThread::PostTask(
-          BrowserThread::IO, FROM_HERE,
-          base::Bind(&StreamContext::InitializeOnIOThread, stream));
-    }
-  }
-
-  return UserDataAdapter<StreamContext>::Get(context, kStreamContextKeyName);
-}
-
-void StreamContext::InitializeOnIOThread() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  registry_.reset(new StreamRegistry());
-}
-
-StreamContext::~StreamContext() {}
-
-}  // namespace content
diff --git a/content/browser/streams/stream_context.h b/content/browser/streams/stream_context.h
deleted file mode 100644
index b4c6d30..0000000
--- a/content/browser/streams/stream_context.h
+++ /dev/null
@@ -1,49 +0,0 @@
-// Copyright (c) 2013 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_BROWSER_STREAMS_STREAM_CONTEXT_H_
-#define CONTENT_BROWSER_STREAMS_STREAM_CONTEXT_H_
-
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/sequenced_task_runner_helpers.h"
-#include "content/public/browser/browser_thread.h"
-
-namespace content {
-class BrowserContext;
-class StreamRegistry;
-
-// A context class that keeps track of StreamRegistry used by the chrome.
-// There is an instance associated with each BrowserContext. There could be
-// multiple URLRequestContexts in the same browser context that refers to the
-// same instance.
-//
-// All methods, except the ctor, are expected to be called on
-// the IO thread (unless specifically called out in doc comments).
-class StreamContext
-    : public base::RefCountedThreadSafe<StreamContext,
-                                        BrowserThread::DeleteOnIOThread> {
- public:
-  StreamContext();
-
-  static StreamContext* GetFor(BrowserContext* browser_context);
-
-  void InitializeOnIOThread();
-
-  StreamRegistry* registry() const { return registry_.get(); }
-
- protected:
-  virtual ~StreamContext();
-
- private:
-  friend class base::DeleteHelper<StreamContext>;
-  friend struct BrowserThread::DeleteOnThread<BrowserThread::IO>;
-
-  scoped_ptr<StreamRegistry> registry_;
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_STREAMS_STREAM_CONTEXT_H_
-
diff --git a/content/browser/streams/stream_read_observer.h b/content/browser/streams/stream_read_observer.h
deleted file mode 100644
index a2b1bdc..0000000
--- a/content/browser/streams/stream_read_observer.h
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright (c) 2013 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_BROWSER_STREAMS_STREAM_READ_OBSERVER_H_
-#define CONTENT_BROWSER_STREAMS_STREAM_READ_OBSERVER_H_
-
-namespace content {
-
-class Stream;
-
-class StreamReadObserver {
- public:
-  // Sent when there is data available to be read from the stream.
-  virtual void OnDataAvailable(Stream* stream) = 0;
-
- protected:
-  virtual ~StreamReadObserver() {}
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_STREAMS_STREAM_READ_OBSERVER_H_
-
diff --git a/content/browser/streams/stream_registry.cc b/content/browser/streams/stream_registry.cc
deleted file mode 100644
index 7159831..0000000
--- a/content/browser/streams/stream_registry.cc
+++ /dev/null
@@ -1,48 +0,0 @@
-// Copyright (c) 2013 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 "content/browser/streams/stream_registry.h"
-
-#include "content/browser/streams/stream.h"
-
-namespace content {
-
-StreamRegistry::StreamRegistry() {
-}
-
-StreamRegistry::~StreamRegistry() {
-}
-
-void StreamRegistry::RegisterStream(scoped_refptr<Stream> stream) {
-  DCHECK(CalledOnValidThread());
-  DCHECK(stream);
-  DCHECK(!stream->url().is_empty());
-  streams_[stream->url()] = stream;
-}
-
-scoped_refptr<Stream> StreamRegistry::GetStream(const GURL& url) {
-  DCHECK(CalledOnValidThread());
-  StreamMap::const_iterator stream = streams_.find(url);
-  if (stream != streams_.end())
-    return stream->second;
-
-  return NULL;
-}
-
-bool StreamRegistry::CloneStream(const GURL& url, const GURL& src_url) {
-  DCHECK(CalledOnValidThread());
-  scoped_refptr<Stream> stream(GetStream(src_url));
-  if (stream) {
-    streams_[url] = stream;
-    return true;
-  }
-  return false;
-}
-
-void StreamRegistry::UnregisterStream(const GURL& url) {
-  DCHECK(CalledOnValidThread());
-  streams_.erase(url);
-}
-
-}  // namespace content
diff --git a/content/browser/streams/stream_registry.h b/content/browser/streams/stream_registry.h
deleted file mode 100644
index eaab7ef..0000000
--- a/content/browser/streams/stream_registry.h
+++ /dev/null
@@ -1,51 +0,0 @@
-// Copyright (c) 2013 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_BROWSER_STREAMS_STREAM_REGISTRY_H_
-#define CONTENT_BROWSER_STREAMS_STREAM_REGISTRY_H_
-
-#include <map>
-
-#include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
-#include "base/threading/non_thread_safe.h"
-#include "content/common/content_export.h"
-#include "googleurl/src/gurl.h"
-
-namespace content {
-
-class Stream;
-
-// Maintains a mapping of blob: URLs to active streams.
-class CONTENT_EXPORT StreamRegistry : public base::NonThreadSafe {
- public:
-  StreamRegistry();
-  virtual ~StreamRegistry();
-
-  // Registers a stream, and sets its URL.
-  void RegisterStream(scoped_refptr<Stream> stream);
-
-  // Clones a stream.  Returns true on success, or false if |src_url| doesn't
-  // exist.
-  bool CloneStream(const GURL& url, const GURL& src_url);
-
-  void UnregisterStream(const GURL& url);
-
-  // Gets the stream associated with |url|.  Returns NULL if there is no such
-  // stream.
-  scoped_refptr<Stream> GetStream(const GURL& url);
-
- private:
-  typedef std::map<GURL, scoped_refptr<Stream> > StreamMap;
-
-  StreamMap streams_;
-
-  DISALLOW_COPY_AND_ASSIGN(StreamRegistry);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_STREAMS_STREAM_REGISTRY_H_
-
-
diff --git a/content/browser/streams/stream_unittest.cc b/content/browser/streams/stream_unittest.cc
deleted file mode 100644
index 46a9eee..0000000
--- a/content/browser/streams/stream_unittest.cc
+++ /dev/null
@@ -1,207 +0,0 @@
-// Copyright (c) 2013 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 "base/message_loop.h"
-#include "base/test/test_simple_task_runner.h"
-#include "content/browser/streams/stream.h"
-#include "content/browser/streams/stream_read_observer.h"
-#include "content/browser/streams/stream_registry.h"
-#include "content/browser/streams/stream_write_observer.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace content {
-
-class StreamTest : public testing::Test {
- public:
-  StreamTest() {}
-
-  virtual void SetUp() OVERRIDE {
-    registry_.reset(new StreamRegistry());
-  }
-
-  // Create a new IO buffer of the given |buffer_size| and fill it with random
-  // data.
-  scoped_refptr<net::IOBuffer> NewIOBuffer(size_t buffer_size) {
-    scoped_refptr<net::IOBuffer> buffer(new net::IOBuffer(buffer_size));
-    char *bufferp = buffer->data();
-    for (size_t i = 0; i < buffer_size; i++)
-      bufferp[i] = (i + producing_seed_key_) % (1 << sizeof(char));
-    ++producing_seed_key_;
-    return buffer;
-  }
-
- protected:
-  MessageLoop message_loop_;
-  scoped_ptr<StreamRegistry> registry_;
-
- private:
-  int producing_seed_key_;
-};
-
-class TestStreamReader : public StreamReadObserver {
- public:
-  TestStreamReader() : buffer_(new net::GrowableIOBuffer()) {
-  }
-  virtual ~TestStreamReader() {}
-
-  void Read(Stream* stream) {
-    const size_t kBufferSize = 32768;
-    scoped_refptr<net::IOBuffer> buffer(new net::IOBuffer(kBufferSize));
-
-    int bytes_read = 0;
-    while (stream->ReadRawData(buffer, kBufferSize, &bytes_read) ==
-           Stream::STREAM_HAS_DATA) {
-      size_t old_capacity = buffer_->capacity();
-      buffer_->SetCapacity(old_capacity + bytes_read);
-      memcpy(buffer_->data() + old_capacity, buffer->data(), bytes_read);
-    }
-  }
-
-  virtual void OnDataAvailable(Stream* stream) OVERRIDE {
-    Read(stream);
-  }
-
-  scoped_refptr<net::GrowableIOBuffer> buffer() { return buffer_; }
-
- private:
-  scoped_refptr<net::GrowableIOBuffer> buffer_;
-};
-
-class TestStreamWriter : public StreamWriteObserver {
- public:
-  TestStreamWriter() {}
-  virtual ~TestStreamWriter() {}
-
-  void Write(Stream* stream,
-             scoped_refptr<net::IOBuffer> buffer,
-             size_t buffer_size) {
-    stream->AddData(buffer, buffer_size);
-  }
-
-  virtual void OnSpaceAvailable(Stream* stream) OVERRIDE {
-  }
-};
-
-TEST_F(StreamTest, SetReadObserver) {
-  TestStreamReader reader;
-  TestStreamWriter writer;
-
-  GURL url("blob://stream");
-  scoped_refptr<Stream> stream(
-      new Stream(registry_.get(), &writer, GURL(), url));
-  EXPECT_TRUE(stream->SetReadObserver(&reader));
-}
-
-TEST_F(StreamTest, SetReadObserver_SecondFails) {
-  TestStreamReader reader1;
-  TestStreamReader reader2;
-  TestStreamWriter writer;
-
-  GURL url("blob://stream");
-  scoped_refptr<Stream> stream(
-      new Stream(registry_.get(), &writer, GURL(), url));
-  EXPECT_TRUE(stream->SetReadObserver(&reader1));
-  EXPECT_FALSE(stream->SetReadObserver(&reader2));
-}
-
-TEST_F(StreamTest, SetReadObserver_TwoReaders) {
-  TestStreamReader reader1;
-  TestStreamReader reader2;
-  TestStreamWriter writer;
-
-  GURL url("blob://stream");
-  scoped_refptr<Stream> stream(
-      new Stream(registry_.get(), &writer, GURL(), url));
-  EXPECT_TRUE(stream->SetReadObserver(&reader1));
-
-  // Once the first read observer is removed, a new one can be added.
-  stream->RemoveReadObserver(&reader1);
-  EXPECT_TRUE(stream->SetReadObserver(&reader2));
-}
-
-TEST_F(StreamTest, Stream) {
-  TestStreamReader reader;
-  TestStreamWriter writer;
-
-  GURL url("blob://stream");
-  scoped_refptr<Stream> stream(
-      new Stream(registry_.get(), &writer, GURL(), url));
-  EXPECT_TRUE(stream->SetReadObserver(&reader));
-
-  int buffer_size = 1000000;
-  scoped_refptr<net::IOBuffer> buffer(NewIOBuffer(buffer_size));
-  writer.Write(stream, buffer, buffer_size);
-  stream->Finalize();
-  reader.Read(stream);
-  MessageLoop::current()->RunUntilIdle();
-
-  ASSERT_EQ(reader.buffer()->capacity(), buffer_size);
-  ASSERT_EQ(0, memcmp(buffer->data(),
-                      reader.buffer()->data(),
-                      buffer_size));
-}
-
-TEST_F(StreamTest, GetStream) {
-  TestStreamWriter writer;
-
-  GURL url("blob://stream");
-  scoped_refptr<Stream> stream1(
-      new Stream(registry_.get(), &writer, GURL(), url));
-
-  scoped_refptr<Stream> stream2 = registry_->GetStream(url);
-  ASSERT_EQ(stream1, stream2);
-}
-
-TEST_F(StreamTest, GetStream_Missing) {
-  TestStreamWriter writer;
-
-  GURL url1("blob://stream");
-  scoped_refptr<Stream> stream1(
-      new Stream(registry_.get(), &writer, GURL(), url1));
-
-  GURL url2("blob://stream2");
-  scoped_refptr<Stream> stream2 = registry_->GetStream(url2);
-  ASSERT_FALSE(stream2);
-}
-
-TEST_F(StreamTest, CloneStream) {
-  TestStreamWriter writer;
-
-  GURL url1("blob://stream");
-  scoped_refptr<Stream> stream1(
-      new Stream(registry_.get(), &writer, GURL(), url1));
-
-  GURL url2("blob://stream2");
-  ASSERT_TRUE(registry_->CloneStream(url2, url1));
-  scoped_refptr<Stream> stream2 = registry_->GetStream(url2);
-  ASSERT_EQ(stream1, stream2);
-}
-
-TEST_F(StreamTest, CloneStream_Missing) {
-  TestStreamWriter writer;
-
-  GURL url1("blob://stream");
-  scoped_refptr<Stream> stream1(
-      new Stream(registry_.get(), &writer, GURL(), url1));
-
-  GURL url2("blob://stream2");
-  GURL url3("blob://stream3");
-  ASSERT_FALSE(registry_->CloneStream(url2, url3));
-  scoped_refptr<Stream> stream2 = registry_->GetStream(url2);
-  ASSERT_FALSE(stream2);
-}
-
-TEST_F(StreamTest, UnregisterStream) {
-  TestStreamWriter writer;
-
-  GURL url("blob://stream");
-  scoped_refptr<Stream> stream1(
-      new Stream(registry_.get(), &writer, GURL(), url));
-
-  registry_->UnregisterStream(url);
-  scoped_refptr<Stream> stream2 = registry_->GetStream(url);
-  ASSERT_FALSE(stream2);
-}
-
-}  // namespace content
diff --git a/content/browser/streams/stream_write_observer.h b/content/browser/streams/stream_write_observer.h
deleted file mode 100644
index 31d84cd..0000000
--- a/content/browser/streams/stream_write_observer.h
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright (c) 2013 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_BROWSER_STREAMS_STREAM_WRITE_OBSERVER_H_
-#define CONTENT_BROWSER_STREAMS_STREAM_WRITE_OBSERVER_H_
-
-namespace content {
-
-class Stream;
-
-class StreamWriteObserver {
- public:
-  // Sent when space becomes available in the stream, and the source should
-  // resume writing.
-  virtual void OnSpaceAvailable(Stream* stream) = 0;
-
- protected:
-  virtual ~StreamWriteObserver() {}
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_STREAMS_STREAM_WRITE_OBSERVER_H_