Loosen FirstMeaningfulPaint UMA network-idle heuristics

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 008fe0f29e6c1384264ea0ff423e666a68085c5e..f118dc9fb4fccf7edc537ef1bd262598cc75e73e 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -19849,6 +19849,25 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="FirstMeaningfulPaintDetector.FirstMeaningfulPaintOrdering"
+    enum="FirstMeaningfulPaintOrdering">
+  <owner>ksakamoto@chromium.org</owner>
+  <summary>
+    Whether the two variants of First Meaningful Paint reported different value,
+    and if so, which one was reported first.
+  </summary>
+</histogram>
+
+<histogram name="FirstMeaningfulPaintDetector.HadNetworkQuiet"
+    enum="NetworkQuietStatus">
+  <owner>ksakamoto@chromium.org</owner>
+  <summary>
+    Recorded when the page load reached network 0-stable (no active network
+    connection for 0.5 seconds), or network 2-stable (no more than 2 active
+    network connections for 2 seconds).
+  </summary>
+</histogram>
+
 <histogram name="GCM.AndroidGcmReceiverError" enum="GcmReceiverStatus">
   <obsolete>
     Deprecated as of 01/2016. The error has been fixed by GCM. (crbug/580367)
@@ -92877,6 +92896,12 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="20" label=".log"/>
 </enum>
 
+<enum name="FirstMeaningfulPaintOrdering" type="int">
+  <int value="0" label="FMP 0-quiet &lt; FMP 2-quiet"/>
+  <int value="1" label="FMP 0-quiet &gt; FMP 2-quiet"/>
+  <int value="2" label="FMP 0-quiet = FMP 2-quiet"/>
+</enum>
+
 <enum name="FirstMeaningfulPaintSignalStatus" type="int">
   <int value="0" label="No input, network active"/>
   <int value="1" label="Had input, network active"/>
@@ -101121,6 +101146,11 @@ value.
   <int value="6" label="Channel Type Change"/>
 </enum>
 
+<enum name="NetworkQuietStatus" type="int">
+  <int value="0" label="Had network 0-quiet for 0.5 seconds"/>
+  <int value="1" label="Had network 2-quiet for 2 seconds"/>
+</enum>
+
 <enum name="NetworkSecurityType" type="int">
   <summary>
     The security types come from the connman_service_security enum in