Add BeginFrameObserverProxy

ui/compositor/compositor_unittest.cc

Index: ui/compositor/compositor_unittest.cc
diff --git a/ui/compositor/compositor_unittest.cc b/ui/compositor/compositor_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b4a8fdbeb03004fa6caf71c6243b5ba91212b965
--- /dev/null
+++ b/ui/compositor/compositor_unittest.cc
@@ -0,0 +1,125 @@
+// Copyright 2015 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 "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+#include "cc/output/begin_frame_args.h"
+#include "cc/test/begin_frame_args_test.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/compositor/compositor.h"
+#include "ui/compositor/test/context_factories_for_test.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace ui {
+
+namespace {
+
+class FakeTaskRunner : public base::SingleThreadTaskRunner {

[mithro-old, 2015/03/11 03:42:58]

We definitely shouldn't be duplicating this FakeTestRunner class. If we can't
use the SimpleTestTaskRunner, we should look at getting a FakeTestRunner into
the base/test/ directory (or some other common location).

[simonhong, 2015/03/11 16:27:47]

Removed and replaced with TestSimpleTaskRunner.

+ public:
+  FakeTaskRunner() {}
+
+  bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
+                                  const base::Closure& task,
+                                  base::TimeDelta delay) override {
+    return true;
+  }
+  bool PostDelayedTask(const tracked_objects::Location& from_here,
+                       const base::Closure& task,
+                       base::TimeDelta delay) override {
+    return true;
+  }
+  bool RunsTasksOnCurrentThread() const override { return true; }
+
+ protected:
+  ~FakeTaskRunner() override {}
+};
+
+class TestCompositorBeginFrameObserver : public CompositorBeginFrameObserver {

[mithro-old, 2015/03/11 03:42:58]

Looking at this, what you should be using gmock here. 

class MockCompositorBeginFrameObserver : public CompositorBeginFrameObserver {
  MOCK_METHOD1(OnSendBeginFrame, void(const BeginFrameArgs&));
}

MockCompositorBeginFrameObserver obs;
EXPECT_CALL(obs, OnSendBeginFrame(args));

my_method(obs);

https://code.google.com/p/googlemock/wiki/CheatSheet

[simonhong, 2015/03/11 16:27:47]

Thanks for suggestion.
Looks clear with gmock!

+ public:
+  TestCompositorBeginFrameObserver() : send_begin_frame_called_(false) {}
+  ~TestCompositorBeginFrameObserver() override {}
+
+  void OnSendBeginFrame(const cc::BeginFrameArgs& args) override {
+    send_begin_frame_called_ = true;
+  }
+
+  void Reset() {
+    send_begin_frame_called_ = false;
+  }
+
+  bool send_begin_frame_called() { return send_begin_frame_called_; }
+
+ private:
+  bool send_begin_frame_called_;
+};
+
+class BeginFrameWithCompositorTest : public testing::Test {
+ public:
+  BeginFrameWithCompositorTest() {}
+  ~BeginFrameWithCompositorTest() override {}
+
+  // Overridden from testing::Test:
+  void SetUp() override {
+    bool enable_pixel_output = false;
+    ui::ContextFactory* context_factory =
+        InitializeContextFactoryForTests(enable_pixel_output);
+    compositor_task_runner_ = new FakeTaskRunner();
+    compositor_.reset(new ui::Compositor(gfx::kNullAcceleratedWidget,
+                                         context_factory,
+                                         compositor_task_runner_.get()));
+  }
+
+  void TearDown() override {
+    compositor_.reset();
+    TerminateContextFactoryForTests();
+  }
+
+  Compositor* compositor() { return compositor_.get(); }
+
+  cc::BeginFrameArgs missed_begin_frame_args() {
+    return compositor()->MissedBeginFrameArgsForTesting();
+  }
+
+ private:
+  scoped_refptr<base::SingleThreadTaskRunner> compositor_task_runner_;
+  scoped_ptr<ui::Compositor> compositor_;
+
+  DISALLOW_COPY_AND_ASSIGN(BeginFrameWithCompositorTest);
+};
+
+// Tests whether |missed_begin_frame_args_| is used immediately or not when new
+// observer is added.
+TEST_F(BeginFrameWithCompositorTest, AddBeginFrameObserver) {
+  cc::BeginFrameArgs last_args =
+    cc::CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE,
+                                       base::TimeTicks::FromInternalValue(33));
+  cc::BeginFrameArgs new_args =
+    cc::CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE,
+                                       base::TimeTicks::FromInternalValue(55));
+  TestCompositorBeginFrameObserver test_observer;
+
+  // Simulate to trigger new BeginFrame by using |new_args|.
+  compositor()->SendBeginFramesToChildren(new_args);
+  // |new_args| is stored in |missed_begin_frame_args_| in Compositor for using
+  // later added observers.
+  EXPECT_EQ(new_args.frame_time,
+            missed_begin_frame_args().frame_time);
+
+  // When new observer is added, Compositor immediately sends BeginFrame with
+  // |missed_begin_frame_args_| when new observer didn't used it.
+  compositor()->AddBeginFrameObserver(&test_observer, last_args);
+  EXPECT_TRUE(test_observer.send_begin_frame_called());
+  compositor()->RemoveBeginFrameObserver(&test_observer);
+
+  test_observer.Reset();
+  // BeginFrame is not sended immediately because new observer already used
+  // |missed_begin_frame_args_|.
+  compositor()->AddBeginFrameObserver(&test_observer, new_args);
+  EXPECT_FALSE(test_observer.send_begin_frame_called());
+  compositor()->RemoveBeginFrameObserver(&test_observer);
+}
+
+}  // namespace
+}  // namespace ui