Web MIDI: add unit tests for event notification of MidiManagerMac

Add a unit test to check if MidiManagerMac correctly notify clients.
Core MIDI requires that the thread calling MIDIClientCreate() should
run CFRunLoop. MidiManagerMac uses base::Thread to call
MIDIClientCreate() on an assumption that it uses CFRunLoop() inside.
To make the assumption confirmed, implement a test for MidiManagerMac.
The test creates a MIDIDestination and checks if AddOutputPort()
is called responded to the MIDIDestination.

BUG=422333
TEST=media_unittests

Review URL: https://codereview.chromium.org/666693002

Cr-Commit-Position: refs/heads/master@{#317247}

media/BUILD.gn

@@ -662,8 +662,10 @@ test("media_unittests") {
   }
 
   if (is_mac) {
-    sources +=
-        [ "video/capture/mac/video_capture_device_factory_mac_unittest.mm" ]
+    sources += [
+      "midi/midi_manager_mac_unittest.cc",
+      "video/capture/mac/video_capture_device_factory_mac_unittest.mm",
+    ]
   }
 
   #      include_dirs += [

media/media.gyp

@@ -1391,6 +1391,7 @@
         }],
         ['OS=="mac"', {
           'sources': [
+            'midi/midi_manager_mac_unittest.cc',
             'video/capture/mac/video_capture_device_factory_mac_unittest.mm',
           ]
         }],

media/midi/midi_manager_mac_unittest.cc

@@ -0,0 +1,126 @@
+// Copyright 2015 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 "media/midi/midi_manager_mac.h"
+
+#include <CoreMIDI/MIDIServices.h>
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+
+namespace {
+
+void Noop(const MIDIPacketList*, void*, void*) {}
+
+class FakeMidiManagerClient : public MidiManagerClient {
+ public:
+  FakeMidiManagerClient()
+      : result_(MIDI_NOT_SUPPORTED),
+        wait_for_result_(true),
+        wait_for_port_(true) {}
+
+  // MidiManagerClient implementation.
+  void AddInputPort(const MidiPortInfo& info) override {}
+  void AddOutputPort(const MidiPortInfo& info) override {
+    CHECK(!wait_for_result_);
+    info_ = info;
+    wait_for_port_ = false;
+  }
+  void SetInputPortState(uint32 port_index, MidiPortState state) override {}
+  void SetOutputPortState(uint32 port_index, MidiPortState state) override {}
+
+  void CompleteStartSession(MidiResult result) override {
+    EXPECT_TRUE(wait_for_result_);
+    result_ = result;
+    wait_for_result_ = false;
+  }
+
+  void ReceiveMidiData(uint32 port_index, const uint8* data, size_t size,
+                       double timestamp) override {}
+  void AccumulateMidiBytesSent(size_t size) override {}
+
+  MidiResult WaitForResult() {
+    while (wait_for_result_) {
+      base::RunLoop run_loop;
+      run_loop.RunUntilIdle();
+    }
+    return result_;
+  }
+  MidiPortInfo WaitForPort() {
+    while (wait_for_port_) {
+      base::RunLoop run_loop;
+      run_loop.RunUntilIdle();
+    }
+    return info_;
+  }
+
+ private:
+  MidiResult result_;
+  bool wait_for_result_;
+  MidiPortInfo info_;
+  bool wait_for_port_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeMidiManagerClient);
+};
+
+class MidiManagerMacTest : public ::testing::Test {
+ public:
+  MidiManagerMacTest()
+      : manager_(new MidiManagerMac),
+        message_loop_(new base::MessageLoop) {}
+
+ protected:
+  void StartSession(MidiManagerClient* client) {
+    manager_->StartSession(client);
+  }
+  void EndSession(MidiManagerClient* client) {
+    manager_->EndSession(client);
+  }
+
+ private:
+  scoped_ptr<MidiManager> manager_;
+  scoped_ptr<base::MessageLoop> message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(MidiManagerMacTest);
+};
+
+
+TEST_F(MidiManagerMacTest, MidiNotification) {
+  scoped_ptr<FakeMidiManagerClient> client(new FakeMidiManagerClient);
+  StartSession(client.get());
+
+  MidiResult result = client->WaitForResult();
+  EXPECT_EQ(MIDI_OK, result);
+
+  // Create MIDIClient, and MIDIEndpoint as a MIDIDestination. This should
+  // notify MIDIManagerMac as a MIDIObjectAddRemoveNotification.
+  MIDIClientRef midi_client = 0;
+  OSStatus status = MIDIClientCreate(
+      CFSTR("MidiManagerMacTest"), nullptr, nullptr, &midi_client);
+  EXPECT_EQ(noErr, status);
+
+  MIDIEndpointRef ep = 0;
+  status = MIDIDestinationCreate(
+      midi_client, CFSTR("DestinationTest"), Noop, nullptr, &ep);
+  EXPECT_EQ(noErr, status);
+
+  // Wait until the created device is notified to MidiManagerMac.
+  MidiPortInfo info = client->WaitForPort();
+  EXPECT_EQ("DestinationTest", info.name);
+
+  EndSession(client.get());
+  if (ep)
+    MIDIEndpointDispose(ep);
+  if (midi_client)
+    MIDIClientDispose(midi_client);
+}
+
+}  // namespace
+
+}  // namespace media