Revert "Allow MessageFilters to restrict listening to specific message classes"

content/browser/tracing/trace_message_filter.cc

 // Copyright (c) 2012 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 "content/browser/tracing/trace_message_filter.h"
 
 #include "components/tracing/tracing_messages.h"
 #include "content/browser/tracing/tracing_controller_impl.h"
 
 namespace content {
 
-TraceMessageFilter::TraceMessageFilter()
-    : BrowserMessageFilter(TracingMsgStart),
-      has_child_(false),
-      is_awaiting_end_ack_(false),
-      is_awaiting_capture_monitoring_snapshot_ack_(false),
-      is_awaiting_buffer_percent_full_ack_(false) {
+TraceMessageFilter::TraceMessageFilter() :
+    has_child_(false),
+    is_awaiting_end_ack_(false),
+    is_awaiting_capture_monitoring_snapshot_ack_(false),
+    is_awaiting_buffer_percent_full_ack_(false) {
 }
 
 TraceMessageFilter::~TraceMessageFilter() {}
 
 void TraceMessageFilter::OnChannelClosing() {
   if (has_child_) {
     if (is_awaiting_end_ack_)
       OnEndTracingAck(std::vector<std::string>());
 
     if (is_awaiting_capture_monitoring_snapshot_ack_)
@@ skipping 134 matching lines @@
   if (is_awaiting_buffer_percent_full_ack_) {
     is_awaiting_buffer_percent_full_ack_ = false;
     TracingControllerImpl::GetInstance()->OnTraceBufferPercentFullReply(
         this, percent_full);
   } else {
     NOTREACHED();
   }
 }
 
 }  // namespace content