[WIP][NotForLand]: Use Mojo for WebMIDI IPC

content/renderer/media/midi_message_filter.h

Index: content/renderer/media/midi_message_filter.h
diff --git a/content/renderer/media/midi_message_filter.h b/content/renderer/media/midi_message_filter.h
index f7e1a8474a49172d1ab6a8a9a1c481449c9ebc3f..17e66b3309aa6b9184b76a2fa405e04da40073b2 100644
--- a/content/renderer/media/midi_message_filter.h
+++ b/content/renderer/media/midi_message_filter.h
@@ -11,8 +11,11 @@
 #include "base/memory/scoped_ptr.h"
 #include "content/common/content_export.h"
 #include "ipc/message_filter.h"
+#include "media/midi/midi_service.mojom.h"
 #include "media/midi/midi_port_info.h"
 #include "media/midi/midi_result.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
 #include "third_party/WebKit/public/platform/WebMIDIAccessorClient.h"
 
 namespace base {
@@ -21,6 +24,30 @@ class MessageLoopProxy;
 
 namespace content {
 
+class MidiMessageFilter;
+
+// TODO(bashi): Put this in a separate file.
+class MidiServiceClientImpl : public media::MidiServiceClient {
+ public:
+  explicit MidiServiceClientImpl(
+      MidiMessageFilter* midi_message_filter,
+      mojo::InterfaceRequest<MidiServiceClient> request);
+  ~MidiServiceClientImpl() override;
+
+  void AcknowledgeSentData(uint32_t bytes_sent) override;
+  void AddInputPort(media::MidiPortInfoMojoPtr input_port) override;
+  void AddOutputPort(media::MidiPortInfoMojoPtr output_port) override;
+  void DataReceived(uint32_t port,
+                    mojo::Array<uint8_t> data,
+                    double timestamp) override;
+
+ private:
+  // TODO(bashi): Remove this reference.
+  scoped_refptr<MidiMessageFilter> midi_message_filter_;
+
+  mojo::StrongBinding<MidiServiceClient> binding_;
+};
+
 // MessageFilter that handles MIDI messages.
 class CONTENT_EXPORT MidiMessageFilter : public IPC::MessageFilter {
  public:
@@ -100,6 +127,11 @@ class CONTENT_EXPORT MidiMessageFilter : public IPC::MessageFilter {
 
   void HandleAckknowledgeSentData(size_t bytes_sent);
 
+  // MidiService callbacks
+  void DidStartSession(media::MidiResultMojo result);
+
+  media::MidiServicePtr service_;
+
   // IPC sender for Send(); must only be accessed on |io_message_loop_|.
   IPC::Sender* sender_;
 
@@ -130,6 +162,8 @@ class CONTENT_EXPORT MidiMessageFilter : public IPC::MessageFilter {
 
   size_t unacknowledged_bytes_sent_;
 
+  friend class MidiServiceClientImpl;
+
   DISALLOW_COPY_AND_ASSIGN(MidiMessageFilter);
 };