Expand UMA coverage for compositor-handled events and fling FPS

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 f46a8b87c2a38de7735ce4a4eeb88030552d6451..52cafd7c7d0a1ff62987cc88c297fab97fea6068 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -6701,6 +6701,28 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Event.Frequency.Renderer.FlingAnimate" units="hertz">
+  <owner>rbyers@chromium.org</owner>
+  <summary>
+    Emitted after a renderer process main-thread fling curve animation
+    terminates, for any reason, reporting the average animation frequency
+    (animations/second) of the fling instance over its lifetime. This is
+    computed as the number of fling animation ticks divided by the fling
+    animation duration.
+  </summary>
+</histogram>
+
+<histogram name="Event.Frequency.RendererImpl.FlingAnimate" units="hertz">
+  <owner>rbyers@chromium.org</owner>
+  <summary>
+    Emitted after a renderer process impl-thread fling curve animation
+    terminates, for any reason, reporting the average animation frequency
+    (animations/second) of the fling instance over its lifetime. This is
+    computed as the number of fling animation ticks divided by the fling
+    animation duration.
+  </summary>
+</histogram>
+
 <histogram name="Event.GestureCreated" enum="UIEventType">
   <owner>kuscher@google.com</owner>
   <owner>rbyers@chromium.org</owner>
@@ -7045,6 +7067,18 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Event.Latency.RendererImpl" units="microseconds">
+  <owner>rbyers@chromium.org</owner>
+  <summary>
+    Time between input event creation and the renderer impl thread receiving and
+    starting to process the event. For touch events on Windows, we measure from
+    when the event reaches Chrome, whereas on other platforms we use the
+    timestamp from the kernel. On Windows, this metric is only reported when
+    |IsHighResNowFastAndReliable| is true, which will introduce some sampling
+    bias.
+  </summary>
+</histogram>
+
 <histogram name="Event.Latency.RendererImpl.GestureScroll" units="microseconds">
   <obsolete>
     Deprecated 12/2013 and replaced by Event.Latency.RendererImpl.GestureScroll2
@@ -60556,6 +60590,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <suffix name="Undefined" label="For unknown or undefined events."/>
   <affected-histogram name="Event.Latency.Renderer"/>
   <affected-histogram name="Event.Latency.Renderer2"/>
+  <affected-histogram name="Event.Latency.RendererImpl"/>
 </histogram_suffixes>
 
 <histogram_suffixes name="ResourcePrefetchPredictorNetworkTypePrefetch"