Revert of ChannelMojo: Let MessagePipeReader wait "peer closed" signal as well.

ipc/mojo/ipc_message_pipe_reader.cc

 // Copyright 2014 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 "ipc/mojo/ipc_message_pipe_reader.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 143 matching lines @@
 
 void MessagePipeReader::ReadMessagesThenWait() {
   while (true) {
     ReadAvailableMessages();
     if (!pipe_.is_valid())
       break;
     // |Wait()| is safe to call only after all messages are read.
     // If can fail with |MOJO_RESULT_ALREADY_EXISTS| otherwise.
     // Also, we don't use MOJO_HANDLE_SIGNAL_WRITABLE here, expecting buffer in
     // MessagePipe.
-    MojoResult result = async_waiter_->Wait(
-        pipe_.get().value(),
-        MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED);
+    MojoResult result =
+        async_waiter_->Wait(pipe_.get().value(), MOJO_HANDLE_SIGNAL_READABLE);
     // If the result is |MOJO_RESULT_ALREADY_EXISTS|, there could be messages
     // that have been arrived after the last |ReadAvailableMessages()|.
     // We have to consume then and retry in that case.
     if (result != MOJO_RESULT_ALREADY_EXISTS) {
       if (result != MOJO_RESULT_OK) {
         LOG(ERROR) << "Failed to wait on the pipe. Result is " << result;
         OnPipeError(result);
         Close();
       }
 
       break;
     }
   }
 }
 
 void MessagePipeReader::PipeIsReady(MojoResult wait_result) {
   if (wait_result != MOJO_RESULT_OK) {
-    CHECK_NE(wait_result, MOJO_RESULT_ABORTED);
-    LOG(ERROR) << "Pipe got error from the waiter. Closing: " << wait_result;
-    OnPipeError(wait_result);
+    if (wait_result != MOJO_RESULT_ABORTED) {
+      // FAILED_PRECONDITION happens every time the peer is dead so
+      // it isn't worth polluting the log message.
+      LOG_IF(WARNING, wait_result != MOJO_RESULT_FAILED_PRECONDITION)
+          << "Pipe got error from the waiter. Closing: " << wait_result;
+      OnPipeError(wait_result);
+    }
 
     Close();
     return;
   }
 
   ReadMessagesThenWait();
 }
 
 void MessagePipeReader::DelayedDeleter::operator()(
     MessagePipeReader* ptr) const {
   ptr->Close();
   base::MessageLoopProxy::current()->PostTask(
       FROM_HERE, base::Bind(&DeleteNow, ptr));
 }
 
 }  // namespace internal
 }  // namespace IPC