Decouple IPC::MessageFilter from IPC::Channel

components/tracing/child_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 "components/tracing/child_trace_message_filter.h"
 
 #include "base/debug/trace_event.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "components/tracing/tracing_messages.h"
 #include "ipc/ipc_channel.h"
 
 using base::debug::TraceLog;
 
 namespace tracing {
 
 ChildTraceMessageFilter::ChildTraceMessageFilter(
     base::MessageLoopProxy* ipc_message_loop)
-    : channel_(NULL),
+    : sender_(NULL),
       ipc_message_loop_(ipc_message_loop) {}
 
-void ChildTraceMessageFilter::OnFilterAdded(IPC::Channel* channel) {
-  channel_ = channel;
-  channel_->Send(new TracingHostMsg_ChildSupportsTracing());
+void ChildTraceMessageFilter::OnFilterAdded(IPC::Sender* sender) {
+  sender_ = sender;
+  sender_->Send(new TracingHostMsg_ChildSupportsTracing());
 }
 
 void ChildTraceMessageFilter::OnFilterRemoved() {
-  channel_ = NULL;
+  sender_ = NULL;
 }
 
 bool ChildTraceMessageFilter::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ChildTraceMessageFilter, message)
     IPC_MESSAGE_HANDLER(TracingMsg_BeginTracing, OnBeginTracing)
     IPC_MESSAGE_HANDLER(TracingMsg_EndTracing, OnEndTracing)
     IPC_MESSAGE_HANDLER(TracingMsg_EnableMonitoring, OnEnableMonitoring)
     IPC_MESSAGE_HANDLER(TracingMsg_DisableMonitoring, OnDisableMonitoring)
     IPC_MESSAGE_HANDLER(TracingMsg_CaptureMonitoringSnapshot,
@@ skipping 60 matching lines @@
   // CaptureMonitoringSnapshotAck below. We are already on the IO thread,
   // so the OnMonitoringTraceDataCollected calls will not be deferred.
   TraceLog::GetInstance()->FlushButLeaveBufferIntact(
       base::Bind(&ChildTraceMessageFilter::OnMonitoringTraceDataCollected,
                  this));
 }
 
 void ChildTraceMessageFilter::OnGetTraceBufferPercentFull() {
   float bpf = TraceLog::GetInstance()->GetBufferPercentFull();
 
-  channel_->Send(new TracingHostMsg_TraceBufferPercentFullReply(bpf));
+  sender_->Send(new TracingHostMsg_TraceBufferPercentFullReply(bpf));
 }
 
 void ChildTraceMessageFilter::OnSetWatchEvent(const std::string& category_name,
                                               const std::string& event_name) {
   TraceLog::GetInstance()->SetWatchEvent(
       category_name, event_name,
       base::Bind(&ChildTraceMessageFilter::OnWatchEventMatched, this));
 }
 
 void ChildTraceMessageFilter::OnCancelWatchEvent() {
   TraceLog::GetInstance()->CancelWatchEvent();
 }
 
 void ChildTraceMessageFilter::OnWatchEventMatched() {
   if (!ipc_message_loop_->BelongsToCurrentThread()) {
     ipc_message_loop_->PostTask(FROM_HERE,
         base::Bind(&ChildTraceMessageFilter::OnWatchEventMatched, this));
     return;
   }
-  channel_->Send(new TracingHostMsg_WatchEventMatched);
+  sender_->Send(new TracingHostMsg_WatchEventMatched);
 }
 
 void ChildTraceMessageFilter::OnTraceDataCollected(
     const scoped_refptr<base::RefCountedString>& events_str_ptr,
     bool has_more_events) {
   if (!ipc_message_loop_->BelongsToCurrentThread()) {
     ipc_message_loop_->PostTask(FROM_HERE,
         base::Bind(&ChildTraceMessageFilter::OnTraceDataCollected, this,
                    events_str_ptr, has_more_events));
     return;
   }
   if (events_str_ptr->data().size()) {
-    channel_->Send(new TracingHostMsg_TraceDataCollected(
+    sender_->Send(new TracingHostMsg_TraceDataCollected(
         events_str_ptr->data()));
   }
   if (!has_more_events) {
     std::vector<std::string> category_groups;
     TraceLog::GetInstance()->GetKnownCategoryGroups(&category_groups);
-    channel_->Send(new TracingHostMsg_EndTracingAck(category_groups));
+    sender_->Send(new TracingHostMsg_EndTracingAck(category_groups));
   }
 }
 
 void ChildTraceMessageFilter::OnMonitoringTraceDataCollected(
      const scoped_refptr<base::RefCountedString>& events_str_ptr,
      bool has_more_events) {
   if (!ipc_message_loop_->BelongsToCurrentThread()) {
     ipc_message_loop_->PostTask(FROM_HERE,
         base::Bind(&ChildTraceMessageFilter::
                    OnMonitoringTraceDataCollected,
                    this,
                    events_str_ptr,
                    has_more_events));
     return;
   }
-  channel_->Send(new TracingHostMsg_MonitoringTraceDataCollected(
+  sender_->Send(new TracingHostMsg_MonitoringTraceDataCollected(
       events_str_ptr->data()));
 
   if (!has_more_events)
-    channel_->Send(new TracingHostMsg_CaptureMonitoringSnapshotAck());
+    sender_->Send(new TracingHostMsg_CaptureMonitoringSnapshotAck());
 }
 
 }  // namespace tracing