Revert "UMA metrics for fractions of wheel and touch scrolls blocked on the main thread."

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 faa0ab29543263d2611b61c3e17bc5d3e6f65d3d..148fe7692605eab77e3ff4e55485eff5108d48b6 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -53417,17 +53417,6 @@ 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 compositor thread but blocked on the
-    main thread. The last case will happen when there is a blocking event
-    listener.
-  </summary>
-</histogram>
-
 <histogram name="Renderer4.GpuImageDecodeState" enum="GpuImageDecodeState">
   <owner>vmpstr@chromium.org</owner>
   <summary>
@@ -53826,17 +53815,6 @@ 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 compositor thread but blocked on
-    the main thread. The last case will happen when there is a blocking event
-    listener.
-  </summary>
-</histogram>
-
 <histogram name="RendererScheduler.BackgroundRendererMainThreadLoad" units="%">
   <owner>altimin@chromium.org</owner>
   <summary>
@@ -104495,12 +104473,6 @@ 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"/>