Add non-blocking frame rate limiting logic to display list 2D canvas

Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp

Index: Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp
diff --git a/Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp b/Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp
index ca7a88880d15b7deb823a09f662fcf56644e7208..738ee070a19ce71368bb318bc666f0a811acab8b 100644
--- a/Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp
+++ b/Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp
@@ -8,6 +8,8 @@
 
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/ImageBuffer.h"
+#include "public/platform/Platform.h"
+#include "public/platform/WebThread.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
 #include "wtf/OwnPtr.h"
@@ -31,6 +33,7 @@ protected:
         m_imageBuffer = ImageBuffer::create(testSurface.release());
     }
 
+public:
     void testEmptyPicture()
     {
         m_testSurface->initializeCurrentFrame();
@@ -60,23 +63,42 @@ protected:
     {
         m_testSurface->initializeCurrentFrame();
         m_testSurface->getPicture();
-        m_testSurface->willUse();
+        m_testSurface->didDraw();
         expectDisplayListEnabled(true);
         // This will trigger fallback
         m_testSurface->getPicture();
         expectDisplayListEnabled(false);
     }
 
+    void testFrameFinalizedByTaskObserver1()
+    {
+        m_testSurface->initializeCurrentFrame();
+        expectDisplayListEnabled(true);
+        m_testSurface->getPicture();
+        expectDisplayListEnabled(true);
+        m_testSurface->didDraw();
+        expectDisplayListEnabled(true);
+        // Display list will be disabled only after exiting the runLoop
+    }
+    void testFrameFinalizedByTaskObserver2()
+    {
+        expectDisplayListEnabled(false);
+        m_testSurface->getPicture();
+        expectDisplayListEnabled(false);
+        m_testSurface->didDraw();
+        expectDisplayListEnabled(false);
+    }
+
     void testAnimatedWithClear()
     {
         m_testSurface->initializeCurrentFrame();
         m_testSurface->getPicture();
         m_testSurface->didClearCanvas();
-        m_testSurface->willUse();
+        m_testSurface->didDraw();
         m_testSurface->getPicture();
         expectDisplayListEnabled(true);
         // clear after use
-        m_testSurface->willUse();
+        m_testSurface->didDraw();
         m_testSurface->didClearCanvas();
         m_testSurface->getPicture();
         expectDisplayListEnabled(true);
@@ -87,23 +109,123 @@ protected:
         m_testSurface->initializeCurrentFrame();
         m_testSurface->getPicture();
         m_imageBuffer->context()->clearRect(FloatRect(FloatPoint(0, 0), FloatSize(m_testSurface->size())));
-        m_testSurface->willUse();
+        m_testSurface->didDraw();
         m_testSurface->getPicture();
         expectDisplayListEnabled(true);
     }
-private:
+
     void expectDisplayListEnabled(bool displayListEnabled)
     {
         EXPECT_EQ(displayListEnabled, (bool)m_testSurface->m_currentFrame.get());
         EXPECT_EQ(!displayListEnabled, (bool)m_testSurface->m_rasterCanvas.get());
     }
 
+private:
     RecordingImageBufferSurface* m_testSurface;
     OwnPtr<ImageBuffer> m_imageBuffer;
 };
 
 namespace {
 
+// The following test helper class installs a mock platform that provides a mock WebThread
+// for the current thread. The Mock thread is capable of queuing a single non-delyaed task

[Stephen White, 2014/07/29 18:38:55]

Nit: non-delayed

+// and registering a single task observer. The run loop exits immediately after running
+// the single task.
+class AutoInstallCurrentThreadPlatformMock {
+public:
+    AutoInstallCurrentThreadPlatformMock()
+    {
+        m_oldPlatform = blink::Platform::current();
+        blink::Platform::initialize(&m_mockPlatform);
+    }
+
+    ~AutoInstallCurrentThreadPlatformMock()
+    {
+        blink::Platform::initialize(m_oldPlatform);
+    }
+
+private:
+    class CurrentThreadMock : public WebThread {
+    public:
+        CurrentThreadMock() : m_taskObserver(0), m_task(0) { }
+
+        virtual ~CurrentThreadMock()
+        {
+            EXPECT_EQ((Task*)0, m_task);
+        }
+
+        virtual void postTask(Task* task)
+        {
+            EXPECT_EQ((Task*)0, m_task);
+            m_task = task;
+        }
+
+        virtual void postDelayedTask(Task*, long long delayMs) OVERRIDE { ASSERT_NOT_REACHED(); };
+
+        virtual bool isCurrentThread() const OVERRIDE { return true; }
+
+        virtual void addTaskObserver(TaskObserver* taskObserver) OVERRIDE
+        {
+            EXPECT_EQ((TaskObserver*)0, m_taskObserver);
+            m_taskObserver = taskObserver;
+        }
+
+        virtual void removeTaskObserver(TaskObserver* taskObserver) OVERRIDE
+        {
+            EXPECT_EQ(m_taskObserver, taskObserver);
+            m_taskObserver = 0;
+        }
+
+        virtual void enterRunLoop() OVERRIDE
+        {
+            if (m_taskObserver)
+                m_taskObserver->willProcessTask();
+            if (m_task) {
+                m_task->run();
+                delete m_task;
+                m_task = 0;
+            }
+            if (m_taskObserver)
+                m_taskObserver->didProcessTask();
+        }
+
+        virtual void exitRunLoop() OVERRIDE { ASSERT_NOT_REACHED(); }
+
+    private:
+        TaskObserver* m_taskObserver;
+        Task* m_task;
+    };
+
+    class CurrentThreadPlatformMock : public blink::Platform {
+    public:
+        CurrentThreadPlatformMock() { }
+        virtual void cryptographicallyRandomValues(unsigned char* buffer, size_t length) { ASSERT_NOT_REACHED(); }
+        virtual WebThread* currentThread() OVERRIDE { return &m_currentThread; }
+    private:
+        CurrentThreadMock m_currentThread;
+    };
+
+    CurrentThreadPlatformMock m_mockPlatform;
+    blink::Platform* m_oldPlatform;
+};
+
+
+#define DEFINE_TEST_TASK_WRAPPER_CLASS(TEST_METHOD)                                               \
+class TestWrapperTask_ ## TEST_METHOD : public blink::WebThread::Task {                           \
+    public:                                                                                       \
+        TestWrapperTask_ ## TEST_METHOD(RecordingImageBufferSurfaceTest* test) : m_test(test) { } \
+        virtual void run() OVERRIDE { m_test->TEST_METHOD(); }                                    \
+    private:                                                                                      \
+        RecordingImageBufferSurfaceTest* m_test;                                                  \
+};
+
+#define CALL_TEST_TASK_WRAPPER(TEST_METHOD)                                                               \
+    {                                                                                                     \
+        AutoInstallCurrentThreadPlatformMock ctpm;                                                        \
+        blink::Platform::current()->currentThread()->postTask(new TestWrapperTask_ ## TEST_METHOD(this)); \
+        blink::Platform::current()->currentThread()->enterRunLoop();                                      \
+    }
+
 TEST_F(RecordingImageBufferSurfaceTest, testEmptyPicture)
 {
     testEmptyPicture();
@@ -119,19 +241,35 @@ TEST_F(RecordingImageBufferSurfaceTest, testNonAnimatedCanvasUpdate)
     testNonAnimatedCanvasUpdate();
 }
 
+DEFINE_TEST_TASK_WRAPPER_CLASS(testAnimatedWithoutClear)
 TEST_F(RecordingImageBufferSurfaceTest, testAnimatedWithoutClear)
 {
-    testAnimatedWithoutClear();
+    CALL_TEST_TASK_WRAPPER(testAnimatedWithoutClear)
+    expectDisplayListEnabled(false);
+}
+
+DEFINE_TEST_TASK_WRAPPER_CLASS(testFrameFinalizedByTaskObserver1)
+DEFINE_TEST_TASK_WRAPPER_CLASS(testFrameFinalizedByTaskObserver2)
+TEST_F(RecordingImageBufferSurfaceTest, testFrameFinalizedByTaskObserver)
+{
+    CALL_TEST_TASK_WRAPPER(testFrameFinalizedByTaskObserver1)
+    expectDisplayListEnabled(false);
+    CALL_TEST_TASK_WRAPPER(testFrameFinalizedByTaskObserver2)
+    expectDisplayListEnabled(false);
 }
 
+DEFINE_TEST_TASK_WRAPPER_CLASS(testAnimatedWithClear)
 TEST_F(RecordingImageBufferSurfaceTest, testAnimatedWithClear)
 {
-    testAnimatedWithClear();
+    CALL_TEST_TASK_WRAPPER(testAnimatedWithClear)
+    expectDisplayListEnabled(true);
 }
 
+DEFINE_TEST_TASK_WRAPPER_CLASS(testClearRect)
 TEST_F(RecordingImageBufferSurfaceTest, testClearRect)
 {
-    testClearRect();
+    CALL_TEST_TASK_WRAPPER(testClearRect);
+    expectDisplayListEnabled(true);
 }
 
 } // namespace