Remove unused fields found by clang's new Wunused-private-fields.

ipc/ipc_sync_channel_unittest.cc

Index: ipc/ipc_sync_channel_unittest.cc
diff --git a/ipc/ipc_sync_channel_unittest.cc b/ipc/ipc_sync_channel_unittest.cc
index a42196b14b84c76ca764dc2b6c12557985d095e6..f6a659838828edb6c6236392618ae5acd1f78845 100644
--- a/ipc/ipc_sync_channel_unittest.cc
+++ b/ipc/ipc_sync_channel_unittest.cc
@@ -1483,7 +1483,6 @@ class RestrictedDispatchDeadlockClient2 : public Worker {
                                     WaitableEvent* server_ready_event,
                                     WaitableEvent** events)
       : Worker("channel2", Channel::MODE_CLIENT),
-        server_(server),
         server_ready_event_(server_ready_event),
         events_(events),
         received_msg_(false),
@@ -1529,7 +1528,6 @@ class RestrictedDispatchDeadlockClient2 : public Worker {
     }
   }
 
-  RestrictedDispatchDeadlockServer* server_;
   WaitableEvent* server_ready_event_;
   WaitableEvent** events_;
   bool received_msg_;
@@ -1912,6 +1910,9 @@ class VerifiedClient : public Worker {
     bool result = Send(msg);
     DCHECK(result);
     DCHECK_EQ(response, expected_text_);
+    // expected_text_ is only used in the above DCHECK. This line suppresses the
+    // "unused private field" warning in release builds.
+    (void)expected_text_;
 
     VLOG(1) << __FUNCTION__ << " Received reply: " << response;
     ASSERT_EQ(channel()->peer_pid(), base::GetCurrentProcId());
@@ -1919,7 +1920,6 @@ class VerifiedClient : public Worker {
   }
 
  private:
-  bool pump_during_send_;
   std::string expected_text_;
 };