[BitmapImage] Don't destroy lazy-decoded frames

Source/platform/graphics/BitmapImage.cpp

Index: Source/platform/graphics/BitmapImage.cpp
diff --git a/Source/platform/graphics/BitmapImage.cpp b/Source/platform/graphics/BitmapImage.cpp
index e324ae2238771132d93295642084fe0955851313..29995ff9d0d3cbdbe299b4ece3a98803e0a9dea3 100644
--- a/Source/platform/graphics/BitmapImage.cpp
+++ b/Source/platform/graphics/BitmapImage.cpp
@@ -139,8 +139,16 @@ void BitmapImage::destroyDecodedDataIfNecessary()
     // to one frame at a time.
     static const size_t cLargeAnimationCutoff = 5242880;
     size_t allFrameBytes = 0;
-    for (size_t i = 0; i < m_frames.size(); ++i)
+    for (size_t i = 0; i < m_frames.size(); ++i) {
+        // The memory for lazy-decoded frames is managed externally.
+        if (m_frames[i].m_frame && m_frames[i].m_frame->isLazyGenerated()) {
+            // We don't mix lazy/non-lazy frames.
+            ASSERT(!allFrameBytes);
+            break;
+        }
+
         allFrameBytes += m_frames[i].m_frameBytes;
+    }
 
     if (allFrameBytes > cLargeAnimationCutoff) {
         destroyDecodedData(false);