Record UMA stats for Blink decoded image types

Source/platform/image-decoders/ico/ICOImageDecoder.h

Index: Source/platform/image-decoders/ico/ICOImageDecoder.h
diff --git a/Source/platform/image-decoders/ico/ICOImageDecoder.h b/Source/platform/image-decoders/ico/ICOImageDecoder.h
index 93278863c3ad3c8e155070a1aeb4698a555d0a67..a30e9336755b4e8a3b1a7693995df29be93da49b 100644
--- a/Source/platform/image-decoders/ico/ICOImageDecoder.h
+++ b/Source/platform/image-decoders/ico/ICOImageDecoder.h
@@ -79,7 +79,11 @@ private:
     static bool compareEntries(const IconDirectoryEntry& a, const IconDirectoryEntry& b);
 
     // ImageDecoder:
-    virtual void decodeSize() { decode(0, true); }
+    virtual void decodeSize()
+    {
+        decode(0, true);
+        reportStats(ImageICO);

[Noel Gordon, 2015/07/30 18:11:47]

Considering that each ICO decoder has one or more child decoders, either PNG or
BMP, and those child decoders will reportStats() as well, this approach
over-counts.

Would it be possible do the counting in BitmapImage, or maybe ImageSource, to
avoid over-counting?

BitmapImage has an ImageSource which has an m_decoder, and thus an
m_decoder->filenameExtension().  Perhaps that could be used to centralize where
reportStats() is done, and not over-count?

[urvang, 2015/07/30 18:52:36]

Ah good point, thanks!
But would be have the image width and height at that point for sure? They are
needed to ignore the 1x1 images.

My initial idea was to reportStats() in ImageDecoder::Create() itself, but we
don't have width/height at that point:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

+    }
     size_t decodeFrameCount() override;
     void decode(size_t index) override { decode(index, false); }