tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 86275e44d40e63364085c18179a18ec78aa33ecd..34716bcca940e491601d73b9d69fbc3b39c316fb 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -5213,6 +5213,21 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Blink.UseCounter.AnimatedCSSProperties"
+    enum="MappedCSSProperties">
+  <owner>rbyers@chromium.org</owner>
+  <summary>
+    Records usage of animated CSS properties used on a page, either statically
+    or dynamically, from the time the page is initialised to when it is closed
+    or navigated away from. Each property is counted at most once per page per
+    view.
+  </summary>
+  <details>
+    Refer to Blink.UseCounter.CSSProperties for details. This histogram counts
+    usage of animated CSS properties only.

[Rick Byers, 2017/04/07 17:56:45]

nit: clarify wording a bit, maybe "This histogram counts CSS properties only
when they are animated by a CSS Animation or the Web Animations API.".   

/cc suzyh: Is that characterization correct?  From the code it's obvious to me
that the usecounter is used for CSS @keyframe animations, but does Web
Animations use the same code path?  If not then presumably we should fix it to
also call into this useCounter (though that can happen in a follow-up CL - no
need to block this one since I'm pretty sure including WebAnimations is the
behavior we want from the UseCounter).

+  </details>
+</histogram>
+
 <histogram name="Blink.UseCounter.CSSProperties" enum="MappedCSSProperties">
   <owner>rbyers@chromium.org</owner>
   <summary>
@@ -5258,6 +5273,19 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </details>
 </histogram>
 
+<histogram name="Blink.UseCounter.SVGImage.AnimatedCSSProperties"
+    enum="MappedCSSProperties">
+  <owner>rbyers@chromium.org</owner>
+  <summary>
+    Like Blink.UseCounter.CSSProperties but specifically for the case of CSS

[Rick Byers, 2017/04/07 17:56:45]

s/CSSProperties/AnimatedCSSProperties/

+    properties used inside of an SVG image.
+  </summary>
+  <details>
+    Refer to Blink.UseCounter.SVGImage.CSSProperties for details. This histogram
+    counts usage of animated CSS properties only.
+  </details>
+</histogram>
+
 <histogram name="Blink.UseCounter.SVGImage.CSSProperties"
     enum="MappedCSSProperties">
   <owner>rbyers@chromium.org</owner>