rtc::Buffer: Rename length to size, for conformance with the STL

And add a constructor for creating an uninitialized Buffer of a
specified size.

(I intend to follow up with more Buffer changes, but since it's rather
widely used, the rename is quite noisy and works better as a separate
CL.)

R=tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/48579004

Cr-Commit-Position: refs/heads/master@{#8841}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8841 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/app/webrtc/datachannel.cc b/talk/app/webrtc/datachannel.cc
index 05c934c..1897b73 100644
--- a/talk/app/webrtc/datachannel.cc
+++ b/talk/app/webrtc/datachannel.cc
@@ -330,8 +330,8 @@
   if (was_ever_writable_ && observer_) {
     observer_->OnMessage(*buffer.get());
   } else {
-    if (queued_received_data_.byte_count() + payload.length() >
-            kMaxQueuedReceivedDataBytes) {
+    if (queued_received_data_.byte_count() + payload.size() >
+        kMaxQueuedReceivedDataBytes) {
       LOG(LS_ERROR) << "Queued received data exceeds the max buffer size.";
 
       queued_received_data_.Clear();
diff --git a/talk/app/webrtc/datachannel_unittest.cc b/talk/app/webrtc/datachannel_unittest.cc
index 6a73fbc..ab5dbe9 100644
--- a/talk/app/webrtc/datachannel_unittest.cc
+++ b/talk/app/webrtc/datachannel_unittest.cc
@@ -145,7 +145,7 @@
   for (int i = 0; i < number_of_packets; ++i) {
     EXPECT_TRUE(webrtc_data_channel_->Send(buffer));
   }
-  EXPECT_EQ(buffer.data.length() * number_of_packets,
+  EXPECT_EQ(buffer.data.size() * number_of_packets,
             webrtc_data_channel_->buffered_amount());
 }
 
@@ -359,10 +359,8 @@
 TEST_F(SctpDataChannelTest, ClosedWhenSendBufferFull) {
   SetChannelReady();
 
-  const size_t buffer_size = 1024;
-  rtc::Buffer buffer;
-  buffer.SetLength(buffer_size);
-  memset(buffer.data(), 0, buffer_size);
+  rtc::Buffer buffer(1024);
+  memset(buffer.data(), 0, buffer.size());
 
   webrtc::DataBuffer packet(buffer, true);
   provider_.set_send_blocked(true);
@@ -413,10 +411,8 @@
 // Tests that the DataChannel is closed if the received buffer is full.
 TEST_F(SctpDataChannelTest, ClosedWhenReceivedBufferFull) {
   SetChannelReady();
-  const size_t buffer_size = 1024;
-  rtc::Buffer buffer;
-  buffer.SetLength(buffer_size);
-  memset(buffer.data(), 0, buffer_size);
+  rtc::Buffer buffer(1024);
+  memset(buffer.data(), 0, buffer.size());
 
   cricket::ReceiveDataParams params;
   params.ssrc = 0;
diff --git a/talk/app/webrtc/datachannelinterface.h b/talk/app/webrtc/datachannelinterface.h
index ed113fc..6312262 100644
--- a/talk/app/webrtc/datachannelinterface.h
+++ b/talk/app/webrtc/datachannelinterface.h
@@ -76,7 +76,7 @@
       : data(text.data(), text.length()),
         binary(false) {
   }
-  size_t size() const { return data.length(); }
+  size_t size() const { return data.size(); }
 
   rtc::Buffer data;
   // Indicates if the received data contains UTF-8 or binary data.
diff --git a/talk/app/webrtc/java/jni/peerconnection_jni.cc b/talk/app/webrtc/java/jni/peerconnection_jni.cc
index 7b4228b..7e6072c 100644
--- a/talk/app/webrtc/java/jni/peerconnection_jni.cc
+++ b/talk/app/webrtc/java/jni/peerconnection_jni.cc
@@ -581,9 +581,8 @@
 
   void OnMessage(const DataBuffer& buffer) override {
     ScopedLocalRefFrame local_ref_frame(jni());
-    jobject byte_buffer =
-        jni()->NewDirectByteBuffer(const_cast<char*>(buffer.data.data()),
-                                   buffer.data.length());
+    jobject byte_buffer = jni()->NewDirectByteBuffer(
+        const_cast<char*>(buffer.data.data()), buffer.data.size());
     jobject j_buffer = jni()->NewObject(*j_buffer_class_, j_buffer_ctor_,
                                         byte_buffer, buffer.binary);
     jni()->CallVoidMethod(*j_observer_global_, j_on_message_mid_, j_buffer);
diff --git a/talk/app/webrtc/objc/RTCDataChannel.mm b/talk/app/webrtc/objc/RTCDataChannel.mm
index 07b90d9..a419577 100644
--- a/talk/app/webrtc/objc/RTCDataChannel.mm
+++ b/talk/app/webrtc/objc/RTCDataChannel.mm
@@ -149,7 +149,7 @@
 
 - (NSData*)data {
   return [NSData dataWithBytes:_dataBuffer->data.data()
-                        length:_dataBuffer->data.length()];
+                        length:_dataBuffer->data.size()];
 }
 
 - (BOOL)isBinary {
diff --git a/talk/app/webrtc/sctputils.cc b/talk/app/webrtc/sctputils.cc
index 988f468..8aa902f 100644
--- a/talk/app/webrtc/sctputils.cc
+++ b/talk/app/webrtc/sctputils.cc
@@ -54,7 +54,7 @@
   // Format defined at
   // http://tools.ietf.org/html/draft-jesup-rtcweb-data-protocol-04
 
-  rtc::ByteBuffer buffer(payload.data(), payload.length());
+  rtc::ByteBuffer buffer(payload.data(), payload.size());
 
   uint8 message_type;
   if (!buffer.ReadUInt8(&message_type)) {
@@ -126,7 +126,7 @@
 }
 
 bool ParseDataChannelOpenAckMessage(const rtc::Buffer& payload) {
-  rtc::ByteBuffer buffer(payload.data(), payload.length());
+  rtc::ByteBuffer buffer(payload.data(), payload.size());
 
   uint8 message_type;
   if (!buffer.ReadUInt8(&message_type)) {
diff --git a/talk/app/webrtc/statscollector.cc b/talk/app/webrtc/statscollector.cc
index ef43ff1..f76245d 100644
--- a/talk/app/webrtc/statscollector.cc
+++ b/talk/app/webrtc/statscollector.cc
@@ -538,8 +538,8 @@
   rtc::Buffer der_buffer;
   cert->ToDER(&der_buffer);
   std::string der_base64;
-  rtc::Base64::EncodeFromArray(
-      der_buffer.data(), der_buffer.length(), &der_base64);
+  rtc::Base64::EncodeFromArray(der_buffer.data(), der_buffer.size(),
+                               &der_base64);
 
   StatsReport::Id id(StatsReport::NewTypedId(
       StatsReport::kStatsReportTypeCertificate, fingerprint));
diff --git a/talk/app/webrtc/test/fakedatachannelprovider.h b/talk/app/webrtc/test/fakedatachannelprovider.h
index 41d6737..bf64a94 100644
--- a/talk/app/webrtc/test/fakedatachannelprovider.h
+++ b/talk/app/webrtc/test/fakedatachannelprovider.h
@@ -45,7 +45,7 @@
       return false;
     }
 
-    if (transport_error_ || payload.length() == 0) {
+    if (transport_error_ || payload.size() == 0) {
       *result = cricket::SDR_ERROR;
       return false;
     }
diff --git a/talk/app/webrtc/test/mockpeerconnectionobservers.h b/talk/app/webrtc/test/mockpeerconnectionobservers.h
index c32c82c..40e9001 100644
--- a/talk/app/webrtc/test/mockpeerconnectionobservers.h
+++ b/talk/app/webrtc/test/mockpeerconnectionobservers.h
@@ -100,7 +100,7 @@
 
   virtual void OnStateChange() { state_ = channel_->state(); }
   virtual void OnMessage(const DataBuffer& buffer) {
-    last_message_.assign(buffer.data.data(), buffer.data.length());
+    last_message_.assign(buffer.data.data(), buffer.data.size());
     ++received_message_count_;
   }