[Experiment] Animated image decoder benchmark tool

Source/platform/image-decoders/ImageDecoder.cpp

Index: Source/platform/image-decoders/ImageDecoder.cpp
diff --git a/Source/platform/image-decoders/ImageDecoder.cpp b/Source/platform/image-decoders/ImageDecoder.cpp
index cb5774dffc510ff6718f93165df02db3011adc39..87f54ce2b51bec202dd87354a26536f4779ec158 100644
--- a/Source/platform/image-decoders/ImageDecoder.cpp
+++ b/Source/platform/image-decoders/ImageDecoder.cpp
@@ -198,4 +198,44 @@ size_t ImageDecoder::findRequiredPreviousFrame(size_t frameIndex, bool frameRect
     }
 }
 
+size_t ImageDecoder::countIndependentFrames() const
+{
+    size_t count = 0;
+    for (size_t i = 0; i < m_frameBufferCache.size(); ++i) {
+        if (m_frameBufferCache[i].requiredPreviousFrameIndex() == kNotFound)
+            ++count;
+    }
+    return count;
+}
+
+float ImageDecoder::countAverageDependentFrames() const
+{
+    const size_t numFrames = m_frameBufferCache.size();
+    float total = 0;
+    for (size_t i = 0; i < numFrames; ++i) {
+        const ImageFrame* buffer = &m_frameBufferCache[i];
+        while (buffer->requiredPreviousFrameIndex() != kNotFound) {
+            ++total;
+            buffer = &m_frameBufferCache[buffer->requiredPreviousFrameIndex()];
+        }
+    }
+    return total / numFrames;
+}
+
+size_t ImageDecoder::countMaxDependentFrames() const
+{
+    size_t max = 0;
+    for (size_t i = 0; i < m_frameBufferCache.size(); ++i) {
+        size_t count = 0;
+        const ImageFrame* buffer = &m_frameBufferCache[i];
+        while (buffer->requiredPreviousFrameIndex() != kNotFound) {
+            ++count;
+            buffer = &m_frameBufferCache[buffer->requiredPreviousFrameIndex()];
+        }
+        if (count > max)
+            max = count;
+    }
+    return max;
+}
+
 } // namespace WebCore