Reland of "Mustash: Ensure surfaces submitted to Mus by WM and embedders contain Surfaces with embe…

ui/aura/mus/client_surface_embedder.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/aura/mus/client_surface_embedder.h"
+
+#include "cc/surfaces/surface_reference_factory.h"
+#include "ui/aura/mus/surface_id_handler.h"
+#include "ui/aura/window.h"
+
+namespace aura {
+namespace {
+
+// TODO(mfomitchev, samans): Remove these stub classes once the SurfaceReference
+// work is complete.
+class StubSurfaceReference : public cc::SurfaceReferenceBase {
+ public:
+  StubSurfaceReference(scoped_refptr<const cc::SurfaceReferenceFactory> factory)
+      : cc::SurfaceReferenceBase(factory) {}
+
+  ~StubSurfaceReference() override { Destroy(); }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(StubSurfaceReference);
+};
+
+class StubSurfaceReferenceFactory : public cc::SurfaceReferenceFactory {
+ public:
+  StubSurfaceReferenceFactory() = default;
+
+  // cc::SurfaceReferenceFactory:
+  std::unique_ptr<cc::SurfaceReferenceBase> CreateReference(
+      cc::SurfaceReferenceOwner* owner,
+      const cc::SurfaceId& surface_id) const override {
+    return base::MakeUnique<StubSurfaceReference>(make_scoped_refptr(this));
+  }
+
+ protected:
+  ~StubSurfaceReferenceFactory() override = default;
+
+ private:
+  // cc::SurfaceReferenceFactory:
+  void DestroyReference(cc::SurfaceReferenceBase* surface_ref) const override {}
+
+  DISALLOW_COPY_AND_ASSIGN(StubSurfaceReferenceFactory);
+};
+}  // namespace
+
+ClientSurfaceEmbedder::ClientSurfaceEmbedder(Window* window) : window_(window) {
+  surface_layer_ = base::MakeUnique<ui::Layer>(ui::LAYER_TEXTURED);
+  surface_layer_->SetVisible(true);
+  // The frame provided by the parent window->layer() needs to show through
+  // the surface layer.
+  surface_layer_->SetFillsBoundsOpaquely(false);
+
+  clip_layer_ = base::MakeUnique<ui::Layer>(ui::LAYER_NOT_DRAWN);
+  clip_layer_->SetFillsBoundsOpaquely(false);
+
+  clip_layer_->Add(surface_layer_.get());
+  window_->layer()->Add(clip_layer_.get());
+
+  // Window's layer may contain content from this client (the embedder), e.g.
+  // this is the case with window decorations provided by Window Manager.
+  // This content should appear underneath the content of the embedded client.
+  window_->layer()->StackAtTop(clip_layer_.get());
+
+  // We can't set this on window's layer, because that would clip the window
+  // shadow.
+  clip_layer_->SetMasksToBounds(true);
+}
+
+ClientSurfaceEmbedder::~ClientSurfaceEmbedder() = default;
+
+void ClientSurfaceEmbedder::UpdateSurface(const cc::SurfaceInfo& surface_info) {
+  // TODO(mfomitchev): Currently the frame size may not match the window size.
+  // In the future the surface id will be created by Ash (and used with the
+  // surface layer) when the window resize happens, which will ensure that the
+  // surface size matches the window size (unless a timeout occurs).
+  gfx::Size frame_size = surface_info.size_in_pixels();
+  surface_layer_->SetBounds(
+      gfx::Rect(0, 0, frame_size.width(), frame_size.height()));
+  // Clip to window bounds.
+  clip_layer_->SetBounds(
+      gfx::Rect(0, 0, window_->bounds().width(), window_->bounds().height()));
+
+  surface_layer_->SetShowSurface(
+      surface_info, make_scoped_refptr(new StubSurfaceReferenceFactory));
+}
+
+}  // namespace aura