EDK: Add PlatformHandleWatcher to Channel (and ChannelManager) classes.

mojo/edk/system/data_pipe_impl_unittest.cc

Index: mojo/edk/system/data_pipe_impl_unittest.cc
diff --git a/mojo/edk/system/data_pipe_impl_unittest.cc b/mojo/edk/system/data_pipe_impl_unittest.cc
index 1cf048037b90167901d2a41e71d43790975b1b5b..bee13f76fc501d4a668ed36eade87b0b03f1d67f 100644
--- a/mojo/edk/system/data_pipe_impl_unittest.cc
+++ b/mojo/edk/system/data_pipe_impl_unittest.cc
@@ -321,10 +321,14 @@ class RemoteDataPipeImplTestHelper : public DataPipeImplTestHelper {
 
     embedder::PlatformChannelPair channel_pair;
     channels_[0] = MakeRefCounted<Channel>(&platform_support_);
-    channels_[0]->Init(RawChannel::Create(channel_pair.PassServerHandle()));
+    channels_[0]->Init(io_thread_.task_runner().Clone(),
+                       io_thread_.platform_handle_watcher(),
+                       RawChannel::Create(channel_pair.PassServerHandle()));
     channels_[0]->SetBootstrapEndpoint(std::move(ep0));
     channels_[1] = MakeRefCounted<Channel>(&platform_support_);
-    channels_[1]->Init(RawChannel::Create(channel_pair.PassClientHandle()));
+    channels_[1]->Init(io_thread_.task_runner().Clone(),
+                       io_thread_.platform_handle_watcher(),
+                       RawChannel::Create(channel_pair.PassClientHandle()));
     channels_[1]->SetBootstrapEndpoint(std::move(ep1));
   }