Move output surface fallback from cc to embedders

Having this in cc means that all embedders get this logic and API, even
though only RenderWidgetCompositor and ui::Compositor use it.

This also means that cc no longer has to be robust to null
SetOutputSurface, which makes the API to embedders a bit more
clear.

Review URL: https://codereview.chromium.org/738983002

Cr-Commit-Position: refs/heads/master@{#307767}

2 files changed, 7 insertions, 2 deletions

diff --git a/mojo/services/html_viewer/weblayertreeview_impl.cc b/mojo/services/html_viewer/weblayertreeview_impl.cc
index c0d77b1..d009f3a 100644
--- a/mojo/services/html_viewer/weblayertreeview_impl.cc
+++ b/mojo/services/html_viewer/weblayertreeview_impl.cc
@@ -97,10 +97,14 @@ void WebLayerTreeViewImpl::ApplyViewportDeltas(
   widget_->applyViewportDeltas(scroll_delta, page_scale, top_controls_delta);
 }
 
-void WebLayerTreeViewImpl::RequestNewOutputSurface(bool fallback) {
+void WebLayerTreeViewImpl::RequestNewOutputSurface() {
   layer_tree_host_->SetOutputSurface(output_surface_.Pass());
 }
 
+void WebLayerTreeViewImpl::DidFailToInitializeOutputSurface() {
+  RequestNewOutputSurface();
+}
+
 void WebLayerTreeViewImpl::DidInitializeOutputSurface() {
 }
 
diff --git a/mojo/services/html_viewer/weblayertreeview_impl.h b/mojo/services/html_viewer/weblayertreeview_impl.h
index 3cc53d4..8310ad7 100644
--- a/mojo/services/html_viewer/weblayertreeview_impl.h
+++ b/mojo/services/html_viewer/weblayertreeview_impl.h
@@ -57,7 +57,8 @@ class WebLayerTreeViewImpl : public blink::WebLayerTreeView,
   void ApplyViewportDeltas(const gfx::Vector2d& scroll_delta,
                            float page_scale,
                            float top_controls_delta) override;
-  void RequestNewOutputSurface(bool fallback) override;
+  void RequestNewOutputSurface() override;
+  void DidFailToInitializeOutputSurface() override;
   void DidInitializeOutputSurface() override;
   void WillCommit() override;
   void DidCommit() override;