Reland Use CopyOnWriteBuffer instead of Buffer to avoid unnecessary copies.

webrtc/api/datachannel_unittest.cc

Index: webrtc/api/datachannel_unittest.cc
diff --git a/webrtc/api/datachannel_unittest.cc b/webrtc/api/datachannel_unittest.cc
index 880c2aa8406b3535d720433d7f121974f9380898..5958ec02f855eebc7eef3e9636ce632b123152d3 100644
--- a/webrtc/api/datachannel_unittest.cc
+++ b/webrtc/api/datachannel_unittest.cc
@@ -246,7 +246,7 @@ TEST_F(SctpDataChannelTest, SendUnorderedAfterReceivesOpenAck) {
   cricket::ReceiveDataParams params;
   params.ssrc = init.id;
   params.type = cricket::DMT_CONTROL;
-  rtc::Buffer payload;
+  rtc::CopyOnWriteBuffer payload;
   webrtc::WriteDataChannelOpenAckMessage(&payload);
   dc->OnDataReceived(NULL, params, payload);
 
@@ -404,7 +404,7 @@ TEST_F(SctpDataChannelTest, OpenAckRoleInitialization) {
 TEST_F(SctpDataChannelTest, ClosedWhenSendBufferFull) {
   SetChannelReady();
 
-  rtc::Buffer buffer(1024);
+  rtc::CopyOnWriteBuffer buffer(1024);
   memset(buffer.data(), 0, buffer.size());
 
   webrtc::DataBuffer packet(buffer, true);
@@ -457,7 +457,7 @@ TEST_F(SctpDataChannelTest, RemotePeerRequestClose) {
 // Tests that the DataChannel is closed if the received buffer is full.
 TEST_F(SctpDataChannelTest, ClosedWhenReceivedBufferFull) {
   SetChannelReady();
-  rtc::Buffer buffer(1024);
+  rtc::CopyOnWriteBuffer buffer(1024);
   memset(buffer.data(), 0, buffer.size());
 
   cricket::ReceiveDataParams params;