UMA histogram WebRTC.AecDelayBasedQuality updated

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 1c352d72174a1b7dc69c401f821b33c219a132e0..c5eaea1a16e7e105666dd94c39ed0b184d6a2fee 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -41913,9 +41913,9 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>
     Captures if the estimated delay between rendered and captured audio is out
     of bounds which can cause the Echo Cancellation to fail. This is logged
-    roughly ones every 5 seconds, but only if there is an application that calls
-    GetStats(). The values are logged in three buckets reflecting how well the
-    Echo Cancellation likely performs based on the estimated delay.
+    roughly once every 5 seconds. The values are logged in four buckets
+    reflecting how well the Echo Cancellation likely performs based on the
+    estimated delay.
   </summary>
 </histogram>
 
@@ -44874,12 +44874,14 @@ Therefore, the affected-histogram name has to have at least one dot in it.
 </enum>
 
 <enum name="DelayBasedEchoQuality" type="int">
-  <int value="0"
-      label="Delay in bounds: Echo Cancellation quality most likely good"/>
-  <int value="1"
-      label="Delay spuriously out of bounds: Echo Cancellation may suffer"/>
-  <int value="2"
-      label="Delay out of bounds: Echo Cancellation most likely fails"/>
+  <int value="0" label="Good delays">
+    Echo Cancellation quality most likely good.
+  </int>
+  <int value="1" label="Spurious delays">Echo Cancellation may suffer.</int>
+  <int value="2" label="Poor delays">
+    Echo Cancellation likely fails unless user is using headset.
+  </int>
+  <int value="3" label="Invalid delays">Insufficient amount of data.</int>
 </enum>
 
 <enum name="DesktopCaptureCounters" type="int">