[remoting host] Enable sending of the RTC event log.

This creates a new FileTransferMessageHandler on a separate data
channel, which can send the host's RTC event log as a file-download.

Bug: 1122798
Change-Id: Icb76e63a790054c45d540c5f20222edbd2086b4d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2450891
Commit-Queue: Lambros Lambrou <lambroslambrou@chromium.org>
Reviewed-by: Erik Jensen <rkjnsn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814511}

remoting/host/client_session.cc

@@ -23,6 +23,7 @@
 #include "remoting/host/audio_capturer.h"
 #include "remoting/host/desktop_environment.h"
 #include "remoting/host/file_transfer/file_transfer_message_handler.h"
+#include "remoting/host/file_transfer/rtc_log_file_operations.h"
 #include "remoting/host/host_extension_session.h"
 #include "remoting/host/input_injector.h"
 #include "remoting/host/keyboard_layout_monitor.h"
@@ -42,6 +43,10 @@
 #include "remoting/protocol/video_frame_pump.h"
 #include "third_party/webrtc/modules/desktop_capture/desktop_capturer.h"
 
+namespace {
+constexpr char kRtcLogTransferDataChannelPrefix[] = "rtc-log-transfer-";
+}  // namespace
+
 namespace remoting {
 
 using protocol::ActionRequest;
@@ -185,6 +190,13 @@ void ClientSession::SetCapabilities(
                             base::Unretained(this)));
   }
 
+  if (HasCapability(capabilities_, protocol::kRtcLogTransferCapability)) {
+    data_channel_manager_.RegisterCreateHandlerCallback(
+        kRtcLogTransferDataChannelPrefix,
+        base::BindRepeating(&ClientSession::CreateRtcLogTransferMessageHandler,
+                            base::Unretained(this)));
+  }
+
   std::vector<ActionRequest::Action> supported_actions;
   if (HasCapability(capabilities_, protocol::kSendAttentionSequenceAction))
     supported_actions.push_back(ActionRequest::SEND_ATTENTION_SEQUENCE);
@@ -832,6 +844,14 @@ void ClientSession::CreateFileTransferMessageHandler(
                                  desktop_environment_->CreateFileOperations());
 }
 
+void ClientSession::CreateRtcLogTransferMessageHandler(
+    const std::string& channel_name,
+    std::unique_ptr<protocol::MessagePipe> pipe) {
+  new FileTransferMessageHandler(
+      channel_name, std::move(pipe),
+      std::make_unique<RtcLogFileOperations>(connection_.get()));
+}
+
 void ClientSession::CreateActionMessageHandler(
     std::vector<ActionRequest::Action> capabilities,
     const std::string& channel_name,

remoting/host/client_session.h

@@ -203,6 +203,10 @@ class ClientSession : public protocol::HostStub,
       const std::string& channel_name,
       std::unique_ptr<protocol::MessagePipe> pipe);
 
+  void CreateRtcLogTransferMessageHandler(
+      const std::string& channel_name,
+      std::unique_ptr<protocol::MessagePipe> pipe);
+
   EventHandler* event_handler_;
 
   // Used to create a DesktopEnvironment instance for this session.

remoting/host/it2me_desktop_environment.cc

@@ -85,7 +85,11 @@ It2MeDesktopEnvironment::It2MeDesktopEnvironment(
 }
 
 std::string It2MeDesktopEnvironment::GetCapabilities() const {
-  return protocol::kWebrtcIceSdpRestartAction;
+  std::string capabilities;
+  capabilities += protocol::kWebrtcIceSdpRestartAction;
+  capabilities += " ";
+  capabilities += protocol::kRtcLogTransferCapability;
+  return capabilities;
 }
 
 It2MeDesktopEnvironmentFactory::It2MeDesktopEnvironmentFactory(

remoting/host/me2me_desktop_environment.cc

@@ -67,6 +67,9 @@ std::string Me2MeDesktopEnvironment::GetCapabilities() const {
   capabilities += " ";
   capabilities += protocol::kWebrtcIceSdpRestartAction;
 
+  capabilities += " ";
+  capabilities += protocol::kRtcLogTransferCapability;
+
   if (InputInjector::SupportsTouchEvents()) {
     capabilities += " ";
     capabilities += protocol::kTouchEventsCapability;

remoting/protocol/capability_names.h

@@ -15,6 +15,7 @@ constexpr char kSendInitialResolution[] = "sendInitialResolution";
 constexpr char kRateLimitResizeRequests[] = "rateLimitResizeRequests";
 
 constexpr char kFileTransferCapability[] = "fileTransfer";
+constexpr char kRtcLogTransferCapability[] = "rtcLogTransfer";
 
 // TODO(joedow): Ideally these would be dynamically created via the
 // DataChannelManager, we should consider moving them there if we begin using