Record UMA stats for Blink decoded image types

Source/platform/image-decoders/ImageDecoder.h

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 31 matching lines @@
 #include "wtf/text/WTFString.h"
 
 #if USE(QCMSLIB)
 #include "qcms.h"
 #endif
 
 typedef Vector<char> ColorProfile;
 
 namespace blink {
 
+enum DecodedImageType {
+    // These values are histogrammed over time; do not change their ordinal
+    // values.  When deleting an image type, replace it with a dummy value;
+    // when adding an image type, do so at the bottom (and update DecodedImageTypeMax).
+    // Also, this enum should be in sync with the 'DecodedImageType' enum in
+    // tools/metrics/histograms/histograms.xml
+    ImageUnknown = 0,
+    ImageJPEG,
+    ImagePNG,
+    ImageGIF,
+    ImageWebP,
+    ImageICO,
+    ImageBMP,
+
+    DecodedImageTypeMax = ImageBMP // Must equal the last "real" image type above.
+};
+
 // ImagePlanes can be used to decode color components into provided buffers instead of using an ImageFrame.
 class PLATFORM_EXPORT ImagePlanes {
 public:
     ImagePlanes();
     ImagePlanes(void* planes[3], size_t rowBytes[3]);
 
     void* plane(int);
     size_t rowBytes(int) const;
 
 private:
@@ skipping 257 matching lines @@
     // returns that number.
     virtual size_t decodeFrameCount() { return 1; }
 
     // Performs any additional setup of the requested frame after it has been
     // initially created, e.g. setting a duration or disposal method.
     virtual void initializeNewFrame(size_t) { }
 
     // Decodes the requested frame.
     virtual void decode(size_t) = 0;
 
+    // Report image stats if it's NOT a trivial 1x1 image.
+    void reportStats(DecodedImageType type) const
+    {
+        if (isDecodedSizeAvailable() && (size().width() > 1 || size().height() > 1)) {
+            Platform::current()->histogramEnumeration("Blink.DecodedImageType", type, DecodedImageTypeMax + 1);
+        }
+    }
+
     RefPtr<SharedBuffer> m_data; // The encoded data.
     Vector<ImageFrame, 1> m_frameBufferCache;
     bool m_premultiplyAlpha;
     bool m_ignoreGammaAndColorProfile;
     ImageOrientation m_orientation;
 
     // The maximum amount of memory a decoded image should require. Ideally,
     // image decoders should downsample large images to fit under this limit
     // (and then return the downsampled size from decodedSize()). Ignoring
     // this limit can cause excessive memory use or even crashes on low-
@@ skipping 12 matching lines @@
 
     IntSize m_size;
     bool m_sizeAvailable;
     bool m_isAllDataReceived;
     bool m_failed;
 };
 
 } // namespace blink
 
 #endif