views/mus: Install a mus-friend ContextFactory for tests.

ui/aura/test/mus/test_context_factory.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/test/mus/test_context_factory.h"
+
+#include "base/threading/thread_task_runner_handle.h"
+#include "cc/output/compositor_frame.h"
+#include "cc/output/compositor_frame_sink_client.h"
+#include "cc/scheduler/begin_frame_source.h"
+#include "cc/scheduler/delay_based_time_source.h"
+#include "cc/test/fake_compositor_frame_sink.h"
+
+namespace aura {
+namespace test {
+
+namespace {
+
+class FakeCompositorFrameSink : public cc::FakeCompositorFrameSink {

[danakj, 2017/03/17 14:10:57]

Can this be cc/test/'s FakeCompositorFrameSink?

[sadrul, 2017/03/17 15:31:11]

cc/test's FakeCompositorFrameSink does not install a BFS. That's why I have this
subclass. Should just update cc/tests's FakeCompositorFrameSink?

[danakj, 2017/03/17 15:33:14]

Ya sure! My high level theology here is that one fake class > many fakes all
over the codebase. And add to it to fit ur needs as u go, then other tests can
benefit from those too in the future.

[sadrul, 2017/03/17 16:50:29]

Done.

+ public:
+  FakeCompositorFrameSink()
+      : cc::FakeCompositorFrameSink(cc::TestContextProvider::Create(),
+                                    cc::TestContextProvider::CreateWorker()) {}
+  ~FakeCompositorFrameSink() override = default;
+
+ private:
+  // cc::FakeCompositorFrameSink:
+  bool BindToClient(cc::CompositorFrameSinkClient* client) override {
+    if (!cc::FakeCompositorFrameSink::BindToClient(client))
+      return false;
+    begin_frame_source_ = base::MakeUnique<cc::BackToBackBeginFrameSource>(
+        base::MakeUnique<cc::DelayBasedTimeSource>(
+            base::ThreadTaskRunnerHandle::Get().get()));
+    client_->SetBeginFrameSource(begin_frame_source_.get());
+    return true;
+  }
+
+  std::unique_ptr<cc::BeginFrameSource> begin_frame_source_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeCompositorFrameSink);
+};
+
+}  // namespace
+
+const cc::CompositorFrame& TestContextFactory::GetLastCompositorFrame() const {
+  return *frame_sink_->last_sent_frame();
+}
+
+void TestContextFactory::CreateCompositorFrameSink(

[danakj, 2017/03/17 14:10:57]

Can you put this in ui/compositor/test/ so we don't duplicate this into more
components and name it FakeContextFactory? "Test" isn't a prefix with meaning.
Fake/Mock/Stub have meanings.

[sadrul, 2017/03/17 16:50:29]

Done.

+    base::WeakPtr<ui::Compositor> compositor) {
+  auto frame_sink = base::MakeUnique<FakeCompositorFrameSink>();
+  frame_sink_ = frame_sink.get();
+  compositor->SetCompositorFrameSink(std::move(frame_sink));
+}
+
+scoped_refptr<cc::ContextProvider>
+TestContextFactory::SharedMainThreadContextProvider() {
+  return nullptr;
+}
+
+void TestContextFactory::RemoveCompositor(ui::Compositor* compositor) {
+  frame_sink_ = nullptr;
+}
+
+bool TestContextFactory::DoesCreateTestContexts() {
+  return true;
+}
+
+uint32_t TestContextFactory::GetImageTextureTarget(gfx::BufferFormat format,
+                                                   gfx::BufferUsage usage) {
+  return GL_TEXTURE_2D;
+}
+
+gpu::GpuMemoryBufferManager* TestContextFactory::GetGpuMemoryBufferManager() {
+  return &gpu_memory_buffer_manager_;
+}
+
+cc::TaskGraphRunner* TestContextFactory::GetTaskGraphRunner() {
+  return &task_graph_runner_;
+}
+
+void TestContextFactory::AddObserver(ui::ContextFactoryObserver* observer) {}
+void TestContextFactory::RemoveObserver(ui::ContextFactoryObserver* observer) {}
+
+}  // namespace test
+}  // namespace aura