Add glue between the client and engine for Blimp

blimp/client/compositor/blimp_compositor.cc

Index: blimp/client/compositor/blimp_compositor.cc
diff --git a/blimp/client/compositor/blimp_compositor.cc b/blimp/client/compositor/blimp_compositor.cc
index 96bad8c4fe3d524e6ddb8cc38aeb4b1040a9ae56..fa66ac4328624d061b64a6b52c7780f36b1e359f 100644
--- a/blimp/client/compositor/blimp_compositor.cc
+++ b/blimp/client/compositor/blimp_compositor.cc
@@ -7,6 +7,7 @@
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
+#include "base/numerics/safe_conversions.h"
 #include "base/single_thread_task_runner.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/thread.h"
@@ -17,10 +18,17 @@
 #include "blimp/client/compositor/blimp_output_surface.h"
 #include "blimp/client/compositor/test/dummy_layer_driver.h"
 #include "blimp/common/compositor/blimp_task_graph_runner.h"
+#include "blimp/common/proto/blimp_message.pb.h"
+#include "blimp/common/proto/compositor.pb.h"
+#include "blimp/common/proto/input.pb.h"
+#include "blimp/common/proto/render_widget.pb.h"
+#include "blimp/net/black_hole_blimp_message_processor.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/layer_settings.h"
 #include "cc/output/output_surface.h"
+#include "cc/proto/compositor_message.pb.h"
 #include "cc/trees/layer_tree_host.h"
+#include "net/base/net_errors.h"
 #include "ui/gl/gl_surface.h"
 
 namespace {
@@ -28,6 +36,11 @@ namespace {
 base::LazyInstance<blimp::BlimpTaskGraphRunner> g_task_graph_runner =
     LAZY_INSTANCE_INITIALIZER;
 
+const int kDummyTabId = 0;
+
+base::LazyInstance<blimp::BlackHoleBlimpMessageProcessor>
+    g_black_hole_message_processor = LAZY_INSTANCE_INITIALIZER;
+
 // TODO(dtrainor): Replace this when Layer content comes from the server (see
 // crbug.com/527200 for details).
 base::LazyInstance<blimp::DummyLayerDriver> g_dummy_layer_driver =
@@ -38,9 +51,19 @@ base::LazyInstance<blimp::DummyLayerDriver> g_dummy_layer_driver =
 namespace blimp {
 
 BlimpCompositor::BlimpCompositor(float dp_to_px)
-    : device_scale_factor_(dp_to_px) {}
+    : device_scale_factor_(dp_to_px),
+      window_(gfx::kNullAcceleratedWidget),
+      host_should_be_visible_(false),
+      output_surface_request_pending_(false),
+      remote_proto_channel_receiver_(nullptr),
+      render_widget_processor_(g_black_hole_message_processor.Pointer()) {
+  render_widget_processor_.SetDelegate(kDummyTabId, this);
+}
 
 BlimpCompositor::~BlimpCompositor() {
+  render_widget_processor_.RemoveDelegate(kDummyTabId);
+  SetVisible(false);
+
   // Destroy |host_| first, as it has a reference to the |settings_| and runs
   // tasks on |compositor_thread_|.
   host_.reset();
@@ -50,39 +73,27 @@ BlimpCompositor::~BlimpCompositor() {
 }
 
 void BlimpCompositor::SetVisible(bool visible) {
-  if (visible && !host_) {
-    if (!settings_) {
-      settings_.reset(new cc::LayerTreeSettings);
-      GenerateLayerTreeSettings(settings_.get());
-    }
-
-    // Create the LayerTreeHost
-    cc::LayerTreeHost::InitParams params;
-    params.client = this;
-    params.task_graph_runner = g_task_graph_runner.Pointer();
-    params.main_task_runner = base::ThreadTaskRunnerHandle::Get();
-    params.settings = settings_.get();
-
-    // TODO(dtrainor): Swap this out with the remote client proxy when
-    // implemented.
-    host_ =
-        cc::LayerTreeHost::CreateThreaded(GetCompositorTaskRunner(), &params);
-
+  // For testing.  Remove once we bind to the network layer.
+  if (!host_)
+    CreateLayerTreeHost(nullptr);
+
+  host_should_be_visible_ = visible;
+  if (!host_ || host_->visible() == visible)
+    return;
+
+  if (!visible) {
+    // If not visible, hide the compositor and have it drop it's output surface.
+    DCHECK(host_->visible());
+    host_->SetVisible(false);
+    if (!host_->output_surface_lost())
+      host_->ReleaseOutputSurface();
+  } else {
+    // If visible, show the compositor.  If the compositor had an outstanding
+    // output surface request, trigger the request again so we build the output
+    // surface.
     host_->SetVisible(true);
-    host_->SetViewportSize(viewport_size_);
-    host_->SetDeviceScaleFactor(device_scale_factor_);
-
-    // Build the root Layer.
-    scoped_refptr<cc::Layer> root(cc::Layer::Create(cc::LayerSettings()));
-    host_->SetRootLayer(root);
-
-    // For testing, set the dummy Layer.
-    g_dummy_layer_driver.Pointer()->SetParentLayer(root);
-
-  } else if (!visible && host_) {
-    // Release the LayerTreeHost to free all resources when the compositor is no
-    // longer visible.  This will destroy the underlying compositor components.
-    host_.reset();
+    if (output_surface_request_pending_)
+      RequestNewOutputSurface();
   }
 }
 
@@ -92,6 +103,31 @@ void BlimpCompositor::SetSize(const gfx::Size& size) {
     host_->SetViewportSize(viewport_size_);
 }
 
+void BlimpCompositor::SetAcceleratedWidget(gfx::AcceleratedWidget widget) {
+  if (widget == window_)
+    return;
+
+  DCHECK(window_ == gfx::kNullAcceleratedWidget);
+  window_ = widget;
+
+  // The compositor should not be visible if there is no output surface.
+  DCHECK(!host_ || !host_->visible());
+
+  // This will properly set visibility and will build the output surface if
+  // necessary.
+  SetVisible(host_should_be_visible_);
+}
+
+void BlimpCompositor::ReleaseAcceleratedWidget() {

[Khushal, 2015/11/19 19:28:24]

We should be able to simplify this. The visibility and output surface logic is
so tightly coupled in the implementation here.

How about we document on the API of this class that ReleaseAcceleratedWidget can
only be called if we are invisible, store the visibility status and just DCHECK
that here.

[David Trainor- moved to gerrit, 2015/11/20 17:58:53]

I think this will get simplified when we split out the intermediate class that
manages which BlimpCompositor is currently visible (we'll push the complexity up
there instead of pulling it down from BlimpView).  I'd rather keep BlimpView as
thin as possible for now if I can.

[Khushal, 2015/11/23 17:40:11]

SGTM.

+  if (window_ == gfx::kNullAcceleratedWidget)
+    return;
+
+  // Hide the compositor and drop the output surface if necessary.
+  SetVisible(false);
+
+  window_ = gfx::kNullAcceleratedWidget;
+}
+
 void BlimpCompositor::WillBeginMainFrame() {}
 
 void BlimpCompositor::DidBeginMainFrame() {}
@@ -110,17 +146,24 @@ void BlimpCompositor::ApplyViewportDeltas(
     float top_controls_delta) {}
 
 void BlimpCompositor::RequestNewOutputSurface() {
-  gfx::AcceleratedWidget widget = GetWindow();
-  DCHECK(widget);
+  output_surface_request_pending_ = true;

[Khushal, 2015/11/19 19:28:24]

nit: Have a method HandlePendingOutputSurfaceRequest()? So we call that from
here and SetVisible()?

[David Trainor- moved to gerrit, 2015/11/20 17:58:53]

Done.

+
+  // We might have had a request from a LayerTreeHost that was then
+  // hidden (and hidden means we don't have a native surface).
+  // Also make sure we only handle this once.
+  if (!host_->visible() || window_ == gfx::kNullAcceleratedWidget)
+    return;
 
   scoped_refptr<BlimpContextProvider> context_provider =
-      BlimpContextProvider::Create(widget);
+      BlimpContextProvider::Create(window_);
 
   host_->SetOutputSurface(
       make_scoped_ptr(new BlimpOutputSurface(context_provider)));
 }
 
-void BlimpCompositor::DidInitializeOutputSurface() {}
+void BlimpCompositor::DidInitializeOutputSurface() {
+  output_surface_request_pending_ = false;
+}
 
 void BlimpCompositor::DidFailToInitializeOutputSurface() {}
 
@@ -138,11 +181,78 @@ void BlimpCompositor::RecordFrameTimingEvents(
     scoped_ptr<cc::FrameTimingTracker::CompositeTimingSet> composite_events,
     scoped_ptr<cc::FrameTimingTracker::MainFrameTimingSet> main_frame_events) {}
 
+void BlimpCompositor::SetProtoReceiver(ProtoReceiver* receiver) {
+  remote_proto_channel_receiver_ = receiver;
+}
+
+void BlimpCompositor::SendCompositorProto(
+    const cc::proto::CompositorMessage& proto) {
+  render_widget_processor_.SendCompositorMessage(kDummyTabId, proto);
+}
+
+void BlimpCompositor::OnRenderWidgetInitialized() {
+  // Tear down the output surface connection with the old compositor instance.
+  SetVisible(false);
+
+  // Destroy the old compositor instance.
+  host_.reset();
+
+  // Reset other state.
+  output_surface_request_pending_ = false;
+
+  // Make sure we don't have a receiver at this point.
+  DCHECK(!remote_proto_channel_receiver_);
+}
+
+void BlimpCompositor::OnCompositorMessageReceived(
+    scoped_ptr<cc::proto::CompositorMessage> message) {
+  // TODO(dtrainor, khushalsagar): Look into the CompositorMessage.  If it is
+  // initialize or shutdown, create or destroy |host_|.
+
+  // We should have a receiver if we're getting compositor messages that aren't
+  // initialize.
+  DCHECK(remote_proto_channel_receiver_);
+  remote_proto_channel_receiver_->OnProtoReceived(message.Pass());
+}
+
 void BlimpCompositor::GenerateLayerTreeSettings(
     cc::LayerTreeSettings* settings) {
   PopulateCommonLayerTreeSettings(settings);
 }
 
+void BlimpCompositor::CreateLayerTreeHost(
+    scoped_ptr<cc::proto::CompositorMessage> message) {
+  if (!settings_) {
+    settings_.reset(new cc::LayerTreeSettings);
+    GenerateLayerTreeSettings(settings_.get());
+  }
+
+  // Create the LayerTreeHost
+  cc::LayerTreeHost::InitParams params;
+  params.client = this;
+  params.task_graph_runner = g_task_graph_runner.Pointer();
+  params.main_task_runner = base::ThreadTaskRunnerHandle::Get();
+  params.settings = settings_.get();
+
+  // TODO(dtrainor): Swap this out with the remote client proxy when
+  // implemented.
+  host_ =
+      cc::LayerTreeHost::CreateThreaded(GetCompositorTaskRunner(), &params);
+
+  // If we're supposed to be visible and we have a valid gfx::AcceleratedWidget
+  // make our compositor visible.
+  if (host_should_be_visible_ && window_ != gfx::kNullAcceleratedWidget)
+    host_->SetVisible(true);
+
+  host_->SetViewportSize(viewport_size_);
+  host_->SetDeviceScaleFactor(device_scale_factor_);
+
+  // For testing, set the dummy Layer.
+  scoped_refptr<cc::Layer> root(cc::Layer::Create(cc::LayerSettings()));
+  host_->SetRootLayer(root);
+  g_dummy_layer_driver.Pointer()->SetParentLayer(root);
+}
+
 scoped_refptr<base::SingleThreadTaskRunner>
 BlimpCompositor::GetCompositorTaskRunner() {
   if (compositor_thread_)