Remove multi-frame image decoder when the image is completely decoded

Source/platform/graphics/ImageFrameGeneratorTest.cpp

Index: Source/platform/graphics/ImageFrameGeneratorTest.cpp
diff --git a/Source/platform/graphics/ImageFrameGeneratorTest.cpp b/Source/platform/graphics/ImageFrameGeneratorTest.cpp
index e49be9b60581d1cf76f96d6f1e1251709b8e6013..129dfd67b79fe0b3fc7545cf0abe28600a5a1a41 100644
--- a/Source/platform/graphics/ImageFrameGeneratorTest.cpp
+++ b/Source/platform/graphics/ImageFrameGeneratorTest.cpp
@@ -59,6 +59,7 @@ public:
         m_decodersDestroyed = 0;
         m_frameBufferRequestCount = 0;
         m_status = ImageFrame::FrameEmpty;
+        m_frameCount = 1;
     }
 
     virtual void TearDown() override
@@ -83,8 +84,8 @@ public:
         return currentStatus;
     }
 
-    virtual size_t frameCount() override { return 1; }
-    virtual int repetitionCount() const override { return cAnimationNone; }
+    virtual size_t frameCount() override { return m_frameCount; }
+    virtual int repetitionCount() const override { return m_frameCount == 1 ? cAnimationNone:cAnimationLoopOnce; }
     virtual float frameDuration() const override { return 0; }
 
 protected:
@@ -101,6 +102,15 @@ protected:
 
     void setFrameStatus(ImageFrame::Status status)  { m_status = m_nextFrameStatus = status; }
     void setNextFrameStatus(ImageFrame::Status status)  { m_nextFrameStatus = status; }
+    void setFrameCount(size_t count)
+    {
+        m_frameCount = count;
+        if (count > 1) {
+            m_generator.clear();
+            m_generator = ImageFrameGenerator::create(fullSize(), m_data, true, true);
+            useMockImageDecoderFactory();
+        }
+    }
 
     RefPtr<SharedBuffer> m_data;
     RefPtr<ImageFrameGenerator> m_generator;
@@ -108,6 +118,7 @@ protected:
     int m_frameBufferRequestCount;
     ImageFrame::Status m_status;
     ImageFrame::Status m_nextFrameStatus;
+    size_t m_frameCount;
 };
 
 TEST_F(ImageFrameGeneratorTest, incompleteDecode)
@@ -179,8 +190,8 @@ TEST_F(ImageFrameGeneratorTest, frameHasAlpha)
     setFrameStatus(ImageFrame::FramePartial);
 
     char buffer[100 * 100 * 4];
-    m_generator->decodeAndScale(imageInfo(), 1, buffer, 100 * 4);
-    EXPECT_TRUE(m_generator->hasAlpha(1));
+    m_generator->decodeAndScale(imageInfo(), 0, buffer, 100 * 4);
+    EXPECT_TRUE(m_generator->hasAlpha(0));
     EXPECT_EQ(1, m_frameBufferRequestCount);
 
     ImageDecoder* tempDecoder = 0;
@@ -190,9 +201,33 @@ TEST_F(ImageFrameGeneratorTest, frameHasAlpha)
     ImageDecodingStore::instance()->unlockDecoder(m_generator.get(), tempDecoder);
 
     setFrameStatus(ImageFrame::FrameComplete);
+    m_generator->decodeAndScale(imageInfo(), 0, buffer, 100 * 4);
+    EXPECT_EQ(2, m_frameBufferRequestCount);
+    EXPECT_FALSE(m_generator->hasAlpha(0));
+}
+
+TEST_F(ImageFrameGeneratorTest, removeMultiFrameDecoder)
+{
+    setFrameCount(3);
+    setFrameStatus(ImageFrame::FrameComplete);
+
+    char buffer[100 * 100 * 4];
+    m_generator->decodeAndScale(imageInfo(), 0, buffer, 100 * 4);
+    EXPECT_EQ(1, m_frameBufferRequestCount);
+    EXPECT_EQ(0, m_decodersDestroyed);
+
+    setFrameStatus(ImageFrame::FrameComplete);
+
     m_generator->decodeAndScale(imageInfo(), 1, buffer, 100 * 4);
     EXPECT_EQ(2, m_frameBufferRequestCount);
-    EXPECT_FALSE(m_generator->hasAlpha(1));
+    EXPECT_EQ(0, m_decodersDestroyed);
+
+    setFrameStatus(ImageFrame::FrameComplete);
+
+    // Multi frame decoder should be removed.
+    m_generator->decodeAndScale(imageInfo(), 2, buffer, 100 * 4);
+    EXPECT_EQ(3, m_frameBufferRequestCount);
+    EXPECT_EQ(1, m_decodersDestroyed);
 }
 
 } // namespace blink