[tracing] Add browser-side test for memory dumps.

content/browser/tracing/trace_message_filter.cc

Index: content/browser/tracing/trace_message_filter.cc
diff --git a/content/browser/tracing/trace_message_filter.cc b/content/browser/tracing/trace_message_filter.cc
index 98757279f363fe925dc1e7f056a5628b504afb93..ac91ff652382a7dfcbaa957c8f344b74fcea2330 100644
--- a/content/browser/tracing/trace_message_filter.cc
+++ b/content/browser/tracing/trace_message_filter.cc
@@ -15,6 +15,7 @@ TraceMessageFilter::TraceMessageFilter()
       is_awaiting_end_ack_(false),
       is_awaiting_capture_monitoring_snapshot_ack_(false),
       is_awaiting_buffer_percent_full_ack_(false) {
+  LOG(ERROR) << "TMFFFF CTORRRRR my " << getpid() << " this " << (void*)this;
 }
 
 TraceMessageFilter::~TraceMessageFilter() {}
@@ -35,6 +36,7 @@ void TraceMessageFilter::OnChannelClosing() {
 }
 
 bool TraceMessageFilter::OnMessageReceived(const IPC::Message& message) {
+  //LOG(ERROR) << "TMFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF " << peer_pid() << " my " << getpid() << " this " << (void*)this;
   // Always on IO thread (BrowserMessageFilter guarantee).
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(TraceMessageFilter, message)
@@ -126,6 +128,7 @@ void TraceMessageFilter::SendGlobalMemoryDumpResponse(uint64 dump_guid,
 }
 
 void TraceMessageFilter::OnChildSupportsTracing() {
+  LOG(ERROR) << "OnChildSupportsTracing " << peer_pid() << " my " << getpid() << " this " << (void*)this;
   has_child_ = true;
   TracingControllerImpl::GetInstance()->AddTraceMessageFilter(this);
 }