Revert "Log to UMA why we would load a third-party frame"

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 b8f5b469c231f8e8ff0679bd3969ffb42985be8c..73f04962b4d5dc45e500d66100c1be979fd4ef83 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -27399,9 +27399,6 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="Navigation.DeferredDocumentLoading.StatesV1"
     enum="DocumentStateForDeferredLoading">
-  <obsolete>
-    Deprecated 10/2016 in favor of Navigation.DeferredDocumentLoading.StatesV2.
-  </obsolete>
   <owner>dgrogan@chromium.org</owner>
   <summary>
     Why and if cross-origin documents would be loaded in a world where we defer
@@ -27409,15 +27406,6 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
-<histogram name="Navigation.DeferredDocumentLoading.StatesV2"
-    enum="DocumentStateForDeferredLoadingV2">
-  <owner>dgrogan@chromium.org</owner>
-  <summary>
-    Why and if cross-origin documents would be loaded if we were to defer
-    loading as long as possible.
-  </summary>
-</histogram>
-
 <histogram name="Navigation.EngagementTime.HTTP" units="ms">
   <owner>felt@chromium.org</owner>
   <summary>
@@ -78337,16 +78325,6 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="1" label="WouldLoadBecauseVisible"/>
 </enum>
 
-<enum name="DocumentStateForDeferredLoadingV2" type="int">
-  <int value="0" label="Created"/>
-  <int value="1" label="WouldLoadOutOfProcess"/>
-  <int value="2" label="WouldLoadDisplayNone"/>
-  <int value="3" label="WouldLoadZeroByZero"/>
-  <int value="4" label="WouldLoadAbove"/>
-  <int value="5" label="WouldLoadLeft"/>
-  <int value="6" label="WouldLoadVisible"/>
-</enum>
-
 <enum name="DocumentWriteGatedEvaluation" type="int">
   <int value="0" label="Script too long"/>
   <int value="1" label="No likely external script write"/>