Prioritizing input and compositor tasks in the blink scheduler.

Source/platform/scheduler/DoubleBufferedDequeTest.cpp

Index: Source/platform/scheduler/DoubleBufferedDequeTest.cpp
diff --git a/Source/platform/scheduler/DoubleBufferedDequeTest.cpp b/Source/platform/scheduler/DoubleBufferedDequeTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..0c95cfba9ee91cccd4fd430b353d21ae461d033a
--- /dev/null
+++ b/Source/platform/scheduler/DoubleBufferedDequeTest.cpp
@@ -0,0 +1,54 @@
+// Copyright 2014 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 "config.h"
+#include "platform/scheduler/DoubleBufferedDeque.h"
+
+#include <gtest/gtest.h>
+
+namespace {
+
+using blink::DoubleBufferedDeque;
+
+typedef testing::Test DoubleBufferedDequeTest;
+
+TEST(DoubleBufferedDequeTest, TestIsEmpty)
+{
+    DoubleBufferedDeque<int> queue;
+
+    EXPECT_TRUE(queue.isEmpty());
+    queue.append(1);
+    EXPECT_FALSE(queue.isEmpty());
+}
+
+TEST(DoubleBufferedDequeTest, TestIsEmptyAfterSwapBuffers)
+{
+    DoubleBufferedDeque<int> queue;
+    queue.append(1);
+
+    queue.swapBuffers();
+    EXPECT_TRUE(queue.isEmpty());
+
+    queue.swapBuffers();
+    EXPECT_FALSE(queue.isEmpty());
+}
+
+TEST(DoubleBufferedDequeTest, TestDoubleBuffering)
+{
+    DoubleBufferedDeque<int> queue;

[Sami, 2014/08/08 15:31:13]

It's a minor thing but could you rewrite this test so that it doesn't hang on to
the old buffer after swapBuffers? Doing that in production code would be bad.

[alexclarke, 2014/08/08 15:47:45]

Done.

+    queue.append(1);
+
+    WTF::Deque<int>& firstBuffer = queue.swapBuffers();
+    queue.append(2);
+
+    WTF::Deque<int>& secondBuffer = queue.swapBuffers();
+
+    EXPECT_EQ(1, firstBuffer.takeFirst());
+    EXPECT_EQ(2, secondBuffer.takeFirst());
+
+    EXPECT_EQ(&firstBuffer, &queue.swapBuffers());
+    EXPECT_EQ(&secondBuffer, &queue.swapBuffers());
+}
+
+} // namespace