Add IPC messages to transfer compositor protos

content/renderer/gpu/render_widget_compositor.cc

Index: content/renderer/gpu/render_widget_compositor.cc
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index 641946864ca300aa16117880873e619d7d43443a..1c15f14cf4bb0da49bc10e272d8efcdacd7e3880 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -31,10 +31,12 @@
 #include "cc/output/copy_output_result.h"
 #include "cc/output/latency_info_swap_promise.h"
 #include "cc/output/swap_promise.h"
+#include "cc/proto/compositor_message.pb.h"
 #include "cc/resources/single_release_callback.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/trees/latency_info_swap_promise_monitor.h"
 #include "cc/trees/layer_tree_host.h"
+#include "cc/trees/remote_proto_channel.h"
 #include "components/scheduler/renderer/renderer_scheduler.h"
 #include "content/common/content_switches_internal.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
@@ -215,6 +217,7 @@ RenderWidgetCompositor::RenderWidgetCompositor(
       compositor_deps_(compositor_deps),
       never_visible_(false),
       layout_and_paint_async_callback_(nullptr),
+      remote_proto_channel_receiver_(nullptr),
       weak_factory_(this) {
 }
 
@@ -968,6 +971,17 @@ void RenderWidgetCompositor::DidAbortSwapBuffers() {
   widget_->OnSwapBuffersAborted();
 }
 
+void RenderWidgetCompositor::SetProtoReceiver(ProtoReceiver* receiver) {
+  remote_proto_channel_receiver_ = receiver;
+}
+
+void RenderWidgetCompositor::SendCompositorProto(
+    const cc::proto::CompositorMessage& proto) {
+  std::vector<char> serialized(proto.ByteSize());

[palmer, 2015/11/16 23:00:29]

char isn't really/isn't necessarily a byte; use uint8_t for certainty.

[David Trainor- moved to gerrit, 2015/11/17 00:55:27]

Done.

+  proto.SerializeToArray(serialized.data(), serialized.size());

[palmer, 2015/11/16 23:00:29]

Sadly, SerializeToArray is defined as taking an int as the size, a tpy ewhich
differs in signedness and possibly in width from the size_t that vector::size
returns. For correctness as written (as opposed to correctness by circumstance),
use the safe conversion functions in base/numeric, or manually check that the
size fits into an int.

[David Trainor- moved to gerrit, 2015/11/17 00:55:27]

Done.

+  widget_->ForwardCompositorProto(serialized);
+}
+
 void RenderWidgetCompositor::RecordFrameTimingEvents(
     scoped_ptr<cc::FrameTimingTracker::CompositeTimingSet> composite_events,
     scoped_ptr<cc::FrameTimingTracker::MainFrameTimingSet> main_frame_events) {
@@ -1005,6 +1019,19 @@ void RenderWidgetCompositor::SetSurfaceIdNamespace(
   layer_tree_host_->set_surface_id_namespace(surface_id_namespace);
 }
 
+void RenderWidgetCompositor::OnHandleCompositorProto(
+    const std::vector<char>& proto) {
+  DCHECK(remote_proto_channel_receiver_);
+
+  cc::proto::CompositorMessage deserialized;
+  if (!deserialized.ParseFromArray(proto.data(), proto.size())) {
+    LOG(ERROR) << "Unable to parse compositor proto.";
+    return;
+  }
+
+  remote_proto_channel_receiver_->OnProtoReceived(deserialized);
+}
+
 cc::ManagedMemoryPolicy RenderWidgetCompositor::GetGpuMemoryPolicy(
     const cc::ManagedMemoryPolicy& policy) {
   cc::ManagedMemoryPolicy actual = policy;