Expose synthetic delays through the GPU benchmarking extension

content/browser/tracing/tracing_controller_impl.cc

Index: content/browser/tracing/tracing_controller_impl.cc
diff --git a/content/browser/tracing/tracing_controller_impl.cc b/content/browser/tracing/tracing_controller_impl.cc
index 1340b67e99237802b01190d46d470232eaf02bbe..a1c3148cbbfa19cd841a35681bab1b6c2400e7fc 100644
--- a/content/browser/tracing/tracing_controller_impl.cc
+++ b/content/browser/tracing/tracing_controller_impl.cc
@@ -114,6 +114,7 @@ TracingControllerImpl::TracingControllerImpl() :
     pending_disable_recording_ack_count_(0),
     pending_capture_monitoring_snapshot_ack_count_(0),
     pending_trace_buffer_percent_full_ack_count_(0),
+    pending_configure_synthetic_delay_ack_count_(0),
     maximum_trace_buffer_percent_full_(0),
     // Tracing may have been enabled by ContentMainRunner if kTraceStartup
     // is specified in command line.
@@ -356,6 +357,31 @@ bool TracingControllerImpl::GetTraceBufferPercentFull(
   return true;
 }
 
+void TracingControllerImpl::ConfigureSyntheticDelay(

[nduca, 2013/11/24 19:42:00]

i think you need to configure them all in one go, not one at a time. that'd take
a bit longer than I think is safe.

+    const std::string& name,
+    base::TimeDelta target_duration,
+    base::debug::TraceEventSyntheticDelay::Mode mode,
+    const ConfigureSyntheticDelayCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  base::debug::TraceEventSyntheticDelay* delay =
+      base::debug::TraceEventSyntheticDelay::Lookup(name);
+  delay->SetTargetDuration(target_duration);
+  delay->SetMode(mode);
+
+  pending_configure_synthetic_delay_callback_ = callback;
+  pending_configure_synthetic_delay_ack_count_ = filters_.size() + 1;
+
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+      base::Bind(&TracingControllerImpl::OnConfigureSyntheticDelayAcked,
+                 base::Unretained(this)));
+
+  // Notify all child processes.
+  for (FilterMap::iterator it = filters_.begin(); it != filters_.end(); ++it) {
+    it->get()->SendConfigureSyntheticDelay(name, target_duration, mode);
+  }
+}
+
 void TracingControllerImpl::AddFilter(TraceMessageFilter* filter) {
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
@@ -569,4 +595,21 @@ void TracingControllerImpl::OnTraceBufferPercentFullReply(float percent_full) {
   }
 }
 
+void TracingControllerImpl::OnConfigureSyntheticDelayAcked() {
+  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
+    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+        base::Bind(&TracingControllerImpl::OnConfigureSyntheticDelayAcked,
+                   base::Unretained(this)));
+    return;
+  }
+
+  if (pending_configure_synthetic_delay_ack_count_ == 0)
+    return;
+
+  if (--pending_configure_synthetic_delay_ack_count_ != 0)
+    return;
+
+  pending_configure_synthetic_delay_callback_.Run();
+}
+
 }  // namespace content