Adding unit test for DrawingBuffer's bitmap recycling mechanism

third_party/WebKit/Source/platform/graphics/gpu/DrawingBufferSoftwareRenderingTest.cpp

Index: third_party/WebKit/Source/platform/graphics/gpu/DrawingBufferSoftwareRenderingTest.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/gpu/DrawingBufferSoftwareRenderingTest.cpp b/third_party/WebKit/Source/platform/graphics/gpu/DrawingBufferSoftwareRenderingTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e90e920047009fee31f1a0b771cd858952dff806
--- /dev/null
+++ b/third_party/WebKit/Source/platform/graphics/gpu/DrawingBufferSoftwareRenderingTest.cpp
@@ -0,0 +1,91 @@
+// Copyright 2016 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 "platform/graphics/gpu/DrawingBuffer.h"
+
+#include "cc/resources/single_release_callback.h"
+#include "cc/resources/texture_mailbox.h"
+#include "gpu/command_buffer/client/gles2_interface_stub.h"
+#include "platform/graphics/gpu/DrawingBufferTestHelpers.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+// These unit tests are separate from DrawingBufferTests.cpp because they are built
+// as a part of webkit_unittests instead blink_platform_unittests because the
+// software rendering mode has a dependency on the blink::Platform interface
+// for buffer allocations.
+
+namespace blink {
+namespace {
+
+using namespace testing;
+
+class WebGraphicsContext3DProviderSoftwareRenderingForTests : public WebGraphicsContext3DProvider {
+public:
+    WebGraphicsContext3DProviderSoftwareRenderingForTests(std::unique_ptr<gpu::gles2::GLES2Interface> gl)
+        : m_gl(std::move(gl))
+    {
+    }
+
+    gpu::gles2::GLES2Interface* contextGL() override { return m_gl.get(); }
+    bool isSoftwareRendering() const override { return true; }
+
+    // Not used by WebGL code.
+    GrContext* grContext() override { return nullptr; }
+    bool bindToCurrentThread() override { return false; }
+    gpu::Capabilities getCapabilities() override { return gpu::Capabilities(); }
+    void setLostContextCallback(WebClosure) {}
+    void setErrorMessageCallback(WebFunction<void(const char*, int32_t id)>) {}
+
+private:
+    std::unique_ptr<gpu::gles2::GLES2Interface> m_gl;
+};
+
+class DrawingBufferSoftwareRenderingTest : public Test {
+protected:
+    void SetUp() override
+    {
+        IntSize initialSize(InitialWidth, InitialHeight);
+        std::unique_ptr<GLES2InterfaceForTests> gl = wrapUnique(new GLES2InterfaceForTests);
+        std::unique_ptr<WebGraphicsContext3DProviderSoftwareRenderingForTests> provider = wrapUnique(new WebGraphicsContext3DProviderSoftwareRenderingForTests(std::move(gl)));
+        m_drawingBuffer = DrawingBufferForTests::create(std::move(provider), initialSize, DrawingBuffer::Preserve);
+        CHECK(m_drawingBuffer);
+    }
+
+    RefPtr<DrawingBufferForTests> m_drawingBuffer;
+    bool m_isSoftwareRendering = false;
+};
+
+TEST_F(DrawingBufferSoftwareRenderingTest, bitmapRecycling)
+{
+    cc::TextureMailbox textureMailbox;
+    std::unique_ptr<cc::SingleReleaseCallback> releaseCallback1;
+    std::unique_ptr<cc::SingleReleaseCallback> releaseCallback2;
+    std::unique_ptr<cc::SingleReleaseCallback> releaseCallback3;
+    IntSize initialSize(InitialWidth, InitialHeight);
+    IntSize alternateSize(InitialWidth, AlternateHeight);
+
+    m_drawingBuffer->reset(initialSize);
+    m_drawingBuffer->markContentsChanged();
+    m_drawingBuffer->PrepareTextureMailbox(&textureMailbox, &releaseCallback1); // create a bitmap.
+    EXPECT_EQ(0, m_drawingBuffer->recycledBitmapCount());
+    releaseCallback1->Run(gpu::SyncToken(), false /* lostResource */); // release bitmap to the recycling queue
+    EXPECT_EQ(1, m_drawingBuffer->recycledBitmapCount());
+    m_drawingBuffer->markContentsChanged();
+    m_drawingBuffer->PrepareTextureMailbox(&textureMailbox, &releaseCallback2); // recycle a bitmap.
+    EXPECT_EQ(0, m_drawingBuffer->recycledBitmapCount());
+    releaseCallback2->Run(gpu::SyncToken(), false /* lostResource */); // release bitmap to the recycling queue
+    EXPECT_EQ(1, m_drawingBuffer->recycledBitmapCount());
+    m_drawingBuffer->reset(alternateSize);
+    m_drawingBuffer->markContentsChanged();
+    // Regression test for crbug.com/647896 - Next line must not crash
+    m_drawingBuffer->PrepareTextureMailbox(&textureMailbox, &releaseCallback3); // cause recycling queue to be purged due to resize
+    EXPECT_EQ(0, m_drawingBuffer->recycledBitmapCount());
+    releaseCallback3->Run(gpu::SyncToken(), false /* lostResource */);
+    EXPECT_EQ(1, m_drawingBuffer->recycledBitmapCount());
+
+    m_drawingBuffer->beginDestruction();
+}
+
+} // unnamed namespace
+} // blink