Add a command-line option to enable VP9 encoding.

remoting/host/chromoting_host.cc

 // Copyright (c) 2012 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 "remoting/host/chromoting_host.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
+#include "base/command_line.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "build/build_config.h"
 #include "remoting/base/constants.h"
 #include "remoting/base/logging.h"
 #include "remoting/host/chromoting_host_context.h"
 #include "remoting/host/desktop_environment.h"
 #include "remoting/host/host_config.h"
 #include "remoting/host/input_injector.h"
 #include "remoting/protocol/connection_to_client.h"
 #include "remoting/protocol/client_stub.h"
 #include "remoting/protocol/host_stub.h"
 #include "remoting/protocol/input_stub.h"
 #include "remoting/protocol/session_config.h"
 
 using remoting::protocol::ConnectionToClient;
 using remoting::protocol::InputStub;
 
 namespace remoting {
 
 namespace {
 
+const char kEnableVp9SwitchName[] = "enable-vp9";
+
 const net::BackoffEntry::Policy kDefaultBackoffPolicy = {
   // Number of initial errors (in sequence) to ignore before applying
   // exponential back-off rules.
   0,
 
   // Initial delay for exponential back-off in ms.
   2000,
 
   // Factor by which the waiting time will be multiplied.
   2,
@@ skipping 37 matching lines @@
       started_(false),
       protocol_config_(protocol::CandidateSessionConfig::CreateDefault()),
       login_backoff_(&kDefaultBackoffPolicy),
       authenticating_client_(false),
       reject_authenticating_client_(false),
       enable_curtaining_(false),
       weak_factory_(this) {
   DCHECK(network_task_runner_->BelongsToCurrentThread());
   DCHECK(signal_strategy);
 
-  // VP9 encode is not yet supported.
-  protocol::CandidateSessionConfig::DisableVideoCodec(
-      protocol_config_.get(), protocol::ChannelConfig::CODEC_VP9);
+  // Disable VP9 unless it is explicitly enabled via the command-line.
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(kEnableVp9SwitchName)) {
+    protocol::CandidateSessionConfig::DisableVideoCodec(
+        protocol_config_.get(), protocol::ChannelConfig::CODEC_VP9);
+  }
 
   if (!desktop_environment_factory_->SupportsAudioCapture()) {
     protocol::CandidateSessionConfig::DisableAudioChannel(
         protocol_config_.get());
   }
 }
 
 ChromotingHost::~ChromotingHost() {
   DCHECK(CalledOnValidThread());
 
@@ skipping 227 matching lines @@
   DCHECK(CalledOnValidThread());
 
   while (!clients_.empty()) {
     size_t size = clients_.size();
     clients_.front()->DisconnectSession();
     CHECK_EQ(clients_.size(), size - 1);
   }
 }
 
 }  // namespace remoting