3 files changed, 52 insertions, 0 deletions

diff --git a/content/browser/byte_stream.cc b/content/browser/byte_stream.cc
index f83e8c3..8031815 100644
--- a/content/browser/byte_stream.cc
+++ b/content/browser/byte_stream.cc
@@ -55,6 +55,7 @@ class ByteStreamWriterImpl : public ByteStreamWriter {
   // Overridden from ByteStreamWriter.
   virtual bool Write(scoped_refptr<net::IOBuffer> buffer,
                      size_t byte_count) OVERRIDE;
+  virtual void Flush() OVERRIDE;
   virtual void Close(DownloadInterruptReason status) OVERRIDE;
   virtual void RegisterCallback(const base::Closure& source_callback) OVERRIDE;
 
@@ -215,6 +216,12 @@ bool ByteStreamWriterImpl::Write(
   return (input_contents_size_ + output_size_used_ <= total_buffer_size_);
 }
 
+void ByteStreamWriterImpl::Flush() {
+  DCHECK(my_task_runner_->RunsTasksOnCurrentThread());
+  if (input_contents_size_ > 0)
+    PostToPeer(false, DOWNLOAD_INTERRUPT_REASON_NONE);
+}
+
 void ByteStreamWriterImpl::Close(
     DownloadInterruptReason status) {
   DCHECK(my_task_runner_->RunsTasksOnCurrentThread());
diff --git a/content/browser/byte_stream.h b/content/browser/byte_stream.h
index 49b7674..973e80573 100644
--- a/content/browser/byte_stream.h
+++ b/content/browser/byte_stream.h
@@ -134,6 +134,12 @@ public:
   virtual bool Write(scoped_refptr<net::IOBuffer> buffer,
                      size_t byte_count) = 0;
 
+  // Flushes contents buffered in this writer to the corresponding reader
+  // regardless if buffer filling rate is greater than
+  // kFractionBufferBeforeSending or not. Does nothing if there's no contents
+  // buffered.
+  virtual void Flush() = 0;
+
   // Signal that all data that is going to be sent, has been sent,
   // and provide a status.  |DOWNLOAD_INTERRUPT_REASON_NONE| should be
   // passed for successful completion.
diff --git a/content/browser/byte_stream_unittest.cc b/content/browser/byte_stream_unittest.cc
index ed413da..a585fb7 100644
--- a/content/browser/byte_stream_unittest.cc
+++ b/content/browser/byte_stream_unittest.cc
@@ -146,6 +146,45 @@ TEST_F(ByteStreamTest, ByteStream_PushBack) {
             byte_stream_output->Read(&output_io_buffer, &output_length));
 }
 
+// Confirm that Flush() method makes the writer to send written contents to
+// the reader.
+TEST_F(ByteStreamTest, ByteStream_Flush) {
+  scoped_ptr<ByteStreamWriter> byte_stream_input;
+  scoped_ptr<ByteStreamReader> byte_stream_output;
+  CreateByteStream(
+      message_loop_.message_loop_proxy(), message_loop_.message_loop_proxy(),
+      1024, &byte_stream_input, &byte_stream_output);
+
+  EXPECT_TRUE(Write(byte_stream_input.get(), 1));
+  message_loop_.RunUntilIdle();
+
+  scoped_refptr<net::IOBuffer> output_io_buffer;
+  size_t output_length = 0;
+  // Check that data is not sent to the reader yet.
+  EXPECT_EQ(ByteStreamReader::STREAM_EMPTY,
+            byte_stream_output->Read(&output_io_buffer, &output_length));
+
+  byte_stream_input->Flush();
+  message_loop_.RunUntilIdle();
+
+  EXPECT_EQ(ByteStreamReader::STREAM_HAS_DATA,
+            byte_stream_output->Read(&output_io_buffer, &output_length));
+  EXPECT_TRUE(ValidateIOBuffer(output_io_buffer, output_length));
+
+  // Check that it's ok to Flush() an empty writer.
+  byte_stream_input->Flush();
+  message_loop_.RunUntilIdle();
+
+  EXPECT_EQ(ByteStreamReader::STREAM_EMPTY,
+            byte_stream_output->Read(&output_io_buffer, &output_length));
+
+  byte_stream_input->Close(DOWNLOAD_INTERRUPT_REASON_NONE);
+  message_loop_.RunUntilIdle();
+
+  EXPECT_EQ(ByteStreamReader::STREAM_COMPLETE,
+            byte_stream_output->Read(&output_io_buffer, &output_length));
+}
+
 // Same as above, only use knowledge of the internals to confirm
 // that we're getting pushback even when data's split across the two
 // objects