Add PLT measurement to Resource Prefetching for Mobile Web

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 592e892e83340c18b428e910c66b170b03f750a0..1b9970e6a24cd86bef727b793afd1dd663927dd8 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -27935,6 +27935,75 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="ResourcePrefetchPredictor.NetworkType.NotPrefetched"
+    enum="ResourcePrefetchPredictorNetworkTypeNotPrefetched">
+  <owner>zhenw@chromium.org</owner>
+  <summary>
+    Records the number of non-prefetched pages on each type of network.
+  </summary>
+</histogram>
+
+<histogram name="ResourcePrefetchPredictor.NetworkType.Prefetched"
+    enum="ResourcePrefetchPredictorNetworkTypePrefetched">
+  <owner>zhenw@chromium.org</owner>
+  <summary>
+    Records the number of prefetched pages on each type of network.
+  </summary>
+</histogram>
+
+<histogram name="ResourcePrefetchPredictor.PLT" units="milliseconds">
+  <owner>zhenw@chromium.org</owner>
+  <summary>
+    Page load time. It starts from when the main frame URL request is sent out
+    to when the main frame document load is completed.
+
+    This is recorded for both prefetched and non-prefetched pages.
+  </summary>
+</histogram>
+
+<histogram name="ResourcePrefetchPredictor.PLT.NotPrefetched"
+    units="milliseconds">
+  <owner>zhenw@chromium.org</owner>
+  <summary>
+    Page load time. It starts from when the main frame URL request is sent out
+    to when the main frame document load is completed.
+
+    This is recorded for non-prefetched pages.
+  </summary>
+</histogram>
+
+<histogram name="ResourcePrefetchPredictor.PLT.Prefetched" units="milliseconds">

[Alexei Svitkine (slow), 2014/10/29 17:43:41]

Can you use histogram_suffixes for these with suffixes Prefetched and
NotPrefetched? Note: You can specify separator="." for them.

Then, for the .Host and .Url versions below, you can have another
histogram_suffixes entry that affects ResourcePrefetchPredictor.PLT.Prefetched.

[Zhen Wang, 2014/10/29 18:23:37]

Ah, I didn't know I can specify the separator.

Done.

By the way, is there a way to use suffix for enum? for 
- ResourcePrefetchPredictor.NetworkType.NotPrefetched
- ResourcePrefetchPredictor.NetworkType.Prefetched

I tried. But "enum" is not recognized in tag "histogram_suffixes" or "suffix".

+  <owner>zhenw@chromium.org</owner>
+  <summary>
+    Page load time. It starts from when the main frame URL request is sent out
+    to when the main frame document load is completed.
+
+    This is recorded for prefetched pages.
+  </summary>
+</histogram>
+
+<histogram name="ResourcePrefetchPredictor.PLT.Prefetched.Host"
+    units="milliseconds">
+  <owner>zhenw@chromium.org</owner>
+  <summary>
+    Page load time. It starts from when the main frame URL request is sent out
+    to when the main frame document load is completed.
+
+    This is recorded for pages prefetched based on the host of main frame URL.
+  </summary>
+</histogram>
+
+<histogram name="ResourcePrefetchPredictor.PLT.Prefetched.Url"
+    units="milliseconds">
+  <owner>zhenw@chromium.org</owner>
+  <summary>
+    Page load time. It starts from when the main frame URL request is sent out
+    to when the main frame document load is completed.
+
+    This is recorded for pages prefetched based on main frame URL.
+  </summary>
+</histogram>
+
 <histogram name="SafeBrowsing.EnabledSettingChanged" enum="BooleanEnabled">
   <owner>feng@chromium.org</owner>
   <summary>
@@ -51166,6 +51235,32 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="1" label="Has client"/>
 </enum>
 
+<enum name="ResourcePrefetchPredictorNetworkTypeNotPrefetched" type="int">
+  <int value="0" label="CONNECTION_UNKNOWN"/>
+  <int value="1" label="CONNECTION_ETHERNET"/>
+  <int value="2" label="CONNECTION_WIFI"/>
+  <int value="3" label="CONNECTION_2G"/>
+  <int value="4" label="CONNECTION_3G"/>
+  <int value="5" label="CONNECTION_4G"/>
+  <int value="6" label="CONNECTION_NONE"/>
+  <int value="7" label="CONNECTION_BLUETOOTH"/>
+  <int value="8" label="CONNECTION_CELLULAR"/>
+  <int value="9" label="CONNECTION_ALL"/>
+</enum>
+
+<enum name="ResourcePrefetchPredictorNetworkTypePrefetched" type="int">
+  <int value="0" label="CONNECTION_UNKNOWN"/>
+  <int value="1" label="CONNECTION_ETHERNET"/>
+  <int value="2" label="CONNECTION_WIFI"/>
+  <int value="3" label="CONNECTION_2G"/>
+  <int value="4" label="CONNECTION_3G"/>
+  <int value="5" label="CONNECTION_4G"/>
+  <int value="6" label="CONNECTION_NONE"/>
+  <int value="7" label="CONNECTION_BLUETOOTH"/>
+  <int value="8" label="CONNECTION_CELLULAR"/>
+  <int value="9" label="CONNECTION_ALL"/>
+</enum>
+
 <enum name="ResourceType" type="int">
   <int value="0" label="Main resource"/>
   <int value="1" label="Image"/>
@@ -57396,6 +57491,23 @@ To add a new entry, add it with any value and run test to compute valid value.
   <affected-histogram name="Event.Latency.Renderer2"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="ResourcePrefetchPredictorPLTNetworkTypes">
+  <suffix name="2G" label="Page load time in 2G network."/>
+  <suffix name="3G" label="Page load time in 3G network."/>
+  <suffix name="4G" label="Page load time in 4G network."/>
+  <suffix name="Bluetooth" label="Page load time in bluetooth network."/>
+  <suffix name="Cellular" label="Page load time in cellular network."/>
+  <suffix name="Ethernet" label="Page load time in Ethernet."/>
+  <suffix name="None" label="Page load time without network connection."/>
+  <suffix name="Unknown" label="Page load time in unknown type of network."/>
+  <suffix name="WiFi" label="Page load time in WiFi network."/>
+  <affected-histogram name="ResourcePrefetchPredictor.PLT"/>
+  <affected-histogram name="ResourcePrefetchPredictor.PLT.NotPrefetched"/>
+  <affected-histogram name="ResourcePrefetchPredictor.PLT.Prefetched"/>
+  <affected-histogram name="ResourcePrefetchPredictor.PLT.Prefetched.Host"/>
+  <affected-histogram name="ResourcePrefetchPredictor.PLT.Prefetched.Url"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="SBInterstitial">
   <obsolete>
     deprecated November 10 2012 crrev.com/167056