Histograms - Support histograms for Plugins, GPU

content/common/child_thread.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/common/child_thread.h"
 
 #include "base/allocator/allocator_extension.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/process.h"
 #include "base/string_util.h"
 #include "base/tracked_objects.h"
+#include "content/common/child_histogram_message_filter.h"
 #include "content/common/child_process.h"
 #include "content/common/child_process_messages.h"
 #include "content/common/child_trace_message_filter.h"
 #include "content/common/fileapi/file_system_dispatcher.h"
 #include "content/common/quota_dispatcher.h"
 #include "content/common/resource_dispatcher.h"
 #include "content/common/socket_stream_dispatcher.h"
 #include "content/public/common/content_switches.h"
 #include "ipc/ipc_logging.h"
 #include "ipc/ipc_switches.h"
@@ skipping 29 matching lines @@
   IPC::Logging::GetInstance()->SetIPCSender(this);
 #endif
 
   resource_dispatcher_.reset(new ResourceDispatcher(this));
   socket_stream_dispatcher_.reset(new SocketStreamDispatcher());
   file_system_dispatcher_.reset(new FileSystemDispatcher());
   quota_dispatcher_.reset(new QuotaDispatcher());
 
   sync_message_filter_ =
       new IPC::SyncMessageFilter(ChildProcess::current()->GetShutDownEvent());
+  histogram_message_filter_ = new content::ChildHistogramMessageFilter();
+
+  channel_->AddFilter(histogram_message_filter_.get());

[jar (doing other things), 2012/07/09 23:04:12]

Where is the corresponding code for the profiler?

[ramant (doing other things), 2012/07/11 23:52:54]

ChildThread::OnMessageReceive implemented GetChildProfilerData message.

For histogram_filter, we needed a separate class (ChildHistogramMessageFilter)
because we wanted to derive from  base::HistogramFlattener.

   channel_->AddFilter(sync_message_filter_.get());
   channel_->AddFilter(new ChildTraceMessageFilter());
 }
 
 ChildThread::~ChildThread() {
 #ifdef IPC_MESSAGE_LOG_ENABLED
   IPC::Logging::GetInstance()->SetIPCSender(NULL);
 #endif
 
+  channel_->RemoveFilter(histogram_message_filter_.get());
   channel_->RemoveFilter(sync_message_filter_.get());
 
   // Close this channel before resetting the message loop attached to it so
   // the message loop can call ChannelProxy::Context::OnChannelClosed(), which
   // releases the reference count to this channel.
   channel_->Close();
 
   // The ChannelProxy object caches a pointer to the IPC thread, so need to
   // reset it as it's not guaranteed to outlive this object.
   // NOTE: this also has the side-effect of not closing the main IPC channel to
@@ skipping 195 matching lines @@
   }
 
   // The child process shutdown sequence is a request response based mechanism,
   // where we send out an initial feeler request to the child process host
   // instance in the browser to verify if it's ok to shutdown the child process.
   // The browser then sends back a response if it's ok to shutdown. This avoids
   // race conditions if the process refcount is 0 but there's an IPC message
   // inflight that would addref it.
   Send(new ChildProcessHostMsg_ShutdownRequest);
 }