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 790748cfab6013c941832b528f865b61ac5721bc..6b8d3e1819576bf74ef23b2bc7a7922e5cb438c1 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -13856,6 +13856,19 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Download.ParallelDownload.CreationEvent"
+    enum="ParallelDownloadCreationEvent">
+  <owner>xingliu@chromium.org</owner>
+  <summary>
+    When parallel downloading feature is enabled, a download may be created as
+    parallel download or fall back to normal download based on various factors.
+    Records the total number of parallel and non-parallel downloads created when
+    parallel downloading feature is enabled. Also records the reason why a
+    parallel download falls back to normal download. The reasons are not
+    mutually exclusive.
+  </summary>
+</histogram>
+
 <histogram name="Download.ParallelDownloadAddStreamSuccess"
     enum="BooleanSuccess">
   <owner>xingliu@chromium.org</owner>
@@ -105714,6 +105727,16 @@ from previous Chrome versions.
   <int value="1" label="HRTF"/>
 </enum>
 
+<enum name="ParallelDownloadCreationEvent" type="int">
+  <int value="0" label="Parallel download started"/>
+  <int value="1" label="Fall back to normal download"/>
+  <int value="2" label="No strong validators response headers"/>
+  <int value="3" label="No accept range header"/>
+  <int value="4" label="No content length header"/>
+  <int value="5" label="File size does not meet the requirement."/>
+  <int value="6" label="HTTP connection type mismatch."/>
+</enum>
+
 <enum name="ParsedCookieStatus" type="int">
   <obsolete>
     Deprecated as of 9/2013. Experiment to measure control characters in cookies