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 9f2e0b15e8bdca7ecd820a28c85f0079648e327d..415c766677a0432a1665c63d2acd2099fb949511 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -52649,6 +52649,17 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Renderer4.GestureScrollingThreadStatus"
+    enum="ScrollingThreadStatus">
+  <owner>tdresser@chromium.org</owner>
+  <summary>
+    For every gesture, we record whether the scroll occurred on the main thread,
+    on the compositor thread, or on the copositor thread but blocked on the main

[tdresser, 2017/01/17 20:27:43]

copositor -> compositor

[sahel, 2017/01/19 15:26:31]

Done.

+    thread. The last case will happen when the TouchStartOrMove event listener

[tdresser, 2017/01/17 20:27:43]

This is a bit overly detailed. Perhaps just "The last case will happen when
there is a blocking event listener".

+    property is blocking.
+  </summary>
+</histogram>
+
 <histogram name="Renderer4.GpuImageDecodeState" enum="GpuImageDecodeState">
   <owner>vmpstr@chromium.org</owner>
   <summary>
@@ -53047,6 +53058,17 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Renderer4.WheelScrollingThreadStatus"
+    enum="ScrollingThreadStatus">
+  <owner>tdresser@chromium.org</owner>
+  <summary>
+    For every wheel tick, we record whether the scroll occurred on the main
+    thread, on the compositor thread, or on the copositor thread but blocked on
+    the main thread. The last case will happen when the MouseWheel event
+    listener property is blocking.

[tdresser, 2017/01/17 20:27:43]

Same as above.

[sahel, 2017/01/19 15:26:32]

Done.

+  </summary>
+</histogram>
+
 <histogram name="RendererScheduler.BackgroundRendererMainThreadLoad" units="%">
   <owner>altimin@chromium.org</owner>
   <summary>
@@ -103180,6 +103202,12 @@ value.
   <int value="9" label="Rollback: SBER2 absent so SBER1 must be cleared"/>
 </enum>
 
+<enum name="ScrollingThreadStatus" type="int">
+  <int value="0" label="SCROLLING_ON_COMPOSITOR"/>
+  <int value="1" label="SCROLLING_ON_COMPOSITOR_BLOCKED_ON_MAIN"/>
+  <int value="2" label="SCROLLING_ON_MAIN"/>
+</enum>
+
 <enum name="ScrollThread" type="int">
   <int value="0" label="Scroll on impl-thread"/>
   <int value="1" label="Scroll on main-thread"/>