Revert making HandleWatcher block until no longer waiting on pipe (r285266).

mojo/message_pump/message_pump_mojo.cc

 // Copyright 2013 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 "mojo/message_pump/message_pump_mojo.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/debug/alias.h"
@@ skipping 184 matching lines @@
              handlers_.end());
       WillSignalHandler();
       handlers_[wait_state.handles[wait_many_result.index]]
           .handler->OnHandleReady(wait_state.handles[wait_many_result.index]);
       DidSignalHandler();
     }
   } else {
     switch (result) {
       case MOJO_RESULT_CANCELLED:
       case MOJO_RESULT_FAILED_PRECONDITION:
+      case MOJO_RESULT_INVALID_ARGUMENT:
         RemoveInvalidHandle(wait_state, result, wait_many_result.index);
         break;
       case MOJO_RESULT_DEADLINE_EXCEEDED:
         did_work = false;
         break;
       default:
         base::debug::Alias(&result);
         // Unexpected result is likely fatal, crash so we can determine cause.
         CHECK(false);
     }
@@ skipping 27 matching lines @@
       did_work = true;
     }
   }
   return did_work;
 }
 
 void MessagePumpMojo::RemoveInvalidHandle(const WaitState& wait_state,
                                           MojoResult result,
                                           uint32_t index) {
   // TODO(sky): deal with control pipe going bad.
-  CHECK(result == MOJO_RESULT_FAILED_PRECONDITION ||
+  CHECK(result == MOJO_RESULT_INVALID_ARGUMENT ||
+        result == MOJO_RESULT_FAILED_PRECONDITION ||
         result == MOJO_RESULT_CANCELLED);
   CHECK_NE(index, 0u);  // Indicates the control pipe went bad.
 
   // Remove the handle first, this way if OnHandleError() tries to remove the
   // handle our iterator isn't invalidated.
   Handle handle = wait_state.handles[index];
   CHECK(handlers_.find(handle) != handlers_.end());
   MessagePumpMojoHandler* handler = handlers_[handle].handler;
   RemoveHandler(handle);
   WillSignalHandler();
@@ skipping 46 matching lines @@
 void MessagePumpMojo::WillSignalHandler() {
   FOR_EACH_OBSERVER(Observer, observers_, WillSignalHandler());
 }
 
 void MessagePumpMojo::DidSignalHandler() {
   FOR_EACH_OBSERVER(Observer, observers_, DidSignalHandler());
 }
 
 }  // namespace common
 }  // namespace mojo