Add a full Blimp integration test.

blimp/client/core/compositor/blimp_compositor.cc

Index: blimp/client/core/compositor/blimp_compositor.cc
diff --git a/blimp/client/core/compositor/blimp_compositor.cc b/blimp/client/core/compositor/blimp_compositor.cc
index 91edfe58bc727ee1eed8a4015ba9828108b18f93..02e5c800c566ede27603c5d498a676b517d343d4 100644
--- a/blimp/client/core/compositor/blimp_compositor.cc
+++ b/blimp/client/core/compositor/blimp_compositor.cc
@@ -68,6 +68,7 @@ BlimpCompositor::BlimpCompositor(
       output_surface_request_pending_(false),
       layer_(cc::Layer::Create()),
       remote_proto_channel_receiver_(nullptr),
+      outstanding_commits_(0U),
       weak_ptr_factory_(this) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
@@ -85,12 +86,17 @@ BlimpCompositor::~BlimpCompositor() {
 
   GetEmbedderDeps()->GetSurfaceManager()->InvalidateSurfaceClientId(
       surface_id_allocator_->client_id());
+
+  CheckPendingCommitCounts(true /* flush */);
 }
 
 void BlimpCompositor::SetVisible(bool visible) {
   host_should_be_visible_ = visible;
   if (host_)
     host_->SetVisible(host_should_be_visible_);
+
+  if (!visible)
+    CheckPendingCommitCounts(true /* flush */);
 }
 
 bool BlimpCompositor::OnTouchEvent(const ui::MotionEvent& motion_event) {
@@ -99,6 +105,16 @@ bool BlimpCompositor::OnTouchEvent(const ui::MotionEvent& motion_event) {
   return false;
 }
 
+void BlimpCompositor::NotifyWhenDonePendingCommits(base::Closure callback) {
+  if (outstanding_commits_ == 0 || !host_ || !host_should_be_visible_) {
+    callback.Run();
+    return;
+  }
+
+  pending_commit_trackers_.push_back(
+      std::make_pair(outstanding_commits_, callback));
+}
+
 void BlimpCompositor::RequestNewOutputSurface() {
   DCHECK(!surface_factory_);
   DCHECK(!output_surface_request_pending_);
@@ -115,6 +131,11 @@ void BlimpCompositor::DidInitializeOutputSurface() {
 
 void BlimpCompositor::DidCommitAndDrawFrame() {
   BlimpStats::GetInstance()->Add(BlimpStats::COMMIT, 1);
+
+  DCHECK_GT(outstanding_commits_, 0U);
+  outstanding_commits_--;
+
+  CheckPendingCommitCounts(false /* flush */);
 }
 
 void BlimpCompositor::SetProtoReceiver(ProtoReceiver* receiver) {
@@ -132,6 +153,12 @@ void BlimpCompositor::OnCompositorMessageReceived(
   const cc::proto::CompositorMessageToImpl& to_impl_proto = message->to_impl();
 
   DCHECK(to_impl_proto.has_message_type());
+
+  if (to_impl_proto.message_type() ==
+      cc::proto::CompositorMessageToImpl::START_COMMIT) {
+    outstanding_commits_++;
+  }
+
   switch (to_impl_proto.message_type()) {
     case cc::proto::CompositorMessageToImpl::UNKNOWN:
       NOTIMPLEMENTED() << "Ignoring message of UNKNOWN type";
@@ -329,5 +356,17 @@ void BlimpCompositor::DestroyLayerTreeHost() {
   DCHECK(!remote_proto_channel_receiver_);
 }
 
+void BlimpCompositor::CheckPendingCommitCounts(bool flush) {
+  for (auto it = pending_commit_trackers_.begin();
+       it != pending_commit_trackers_.end();) {
+    if (flush || --it->first == 0) {
+      it->second.Run();
+      it = pending_commit_trackers_.erase(it);
+    } else {
+      ++it;
+    }
+  }
+}
+
 }  // namespace client
 }  // namespace blimp