Revert CompressibleString (and its UMA)

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 00fc159afce5b19a8027bb3adc0a39fec5000c4f..3c5db77ec4602e7d623281943442c02fb6729f3f 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -23614,6 +23614,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="Memory.CompressibleStringCount"
     enum="CompressibleStringCountType">
+  <obsolete>
+    Deprecated as of Aug 2016. CompressibleString has been reverted once at
+    https://crrev.com/2227933002.
+  </obsolete>
   <owner>hajimehoshi@chromium.org</owner>
   <summary>
     This records the frequency with which JavaScript source strings are
@@ -70533,6 +70537,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </enum>
 
 <enum name="CompressibleStringCountType" type="int">
+  <obsolete>
+    Dprecated as of Aug 2016. CompressibleString has been reverted once at
+    https://crrev.com/2227933002.
+  </obsolete>
   <int value="0" label="Compressed in a background tab"/>
   <int value="1" label="Decompressed in a background or a foreground tab"/>
 </enum>