Setting chrome as the default browser is now fixed on Windows 10

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 bf2dd23dba7c7ea3cddffb896bdcc83600b76347..d392b9765d2d5231f255de57aa4b060afd7c2ab0 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -6124,6 +6124,25 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="DefaultBrowser.AsyncSetAsDefault.Duration"
+    units="milliseconds">
+  <owner>pmonette@chromium.org</owner>
+  <summary>
+    How long it took to set Chrome as the default browser asynchronously in
+    Windows 10+. The duration is recorded only on Success, Failure, Abandoned
+    and Retry result codes.
+  </summary>
+</histogram>
+
+<histogram name="DefaultBrowser.AsyncSetAsDefault.Result"
+    enum="DefaultBrowserAsyncAttemptResult">
+  <owner>pmonette@chromium.org</owner>
+  <summary>
+    The count of how many times users were successfully able to set Chrome as
+    the default browser asynchronously in Windows 10+.
+  </summary>
+</histogram>
+
 <histogram name="DefaultBrowser.InteractionResult"
     enum="MakeChromeDefaultResult">
   <owner>gab@chromium.org</owner>
@@ -54785,6 +54804,31 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="6" label="kImageBMP"/>
 </enum>
 
+<enum name="DefaultBrowserAsyncAttemptResult" type="int">
+  <int value="0" label="Success">No errors encountered.</int>
+  <int value="1" label="Already default">
+    Chrome was already the default web client. This counts as a successful
+    attempt.
+  </int>
+  <int value="2" label="Failure">
+    Chrome was not set as the default web client.
+  </int>
+  <int value="3" label="Abandoned">
+    The attempt was abandoned because the observer was destroyed.
+  </int>
+  <int value="4" label="Launch failure">
+    Failed to launch the process to set Chrome as the default web client
+    asynchronously.
+  </int>
+  <int value="5" label="Other worker">
+    Another worker is already in progress to make Chrome the default web client.
+  </int>
+  <int value="6" label="Retry">
+    The user initiated another attempt while the asynchronous operation was
+    already in progress.
+  </int>
+</enum>
+
 <enum name="DefaultBrowserState" type="int">
   <int value="0" label="Not Default"/>
   <int value="1" label="Default"/>
@@ -74477,6 +74521,14 @@ To add a new entry, add it with any value and run test to compute valid value.
   <affected-histogram name="Renderer4.StartToFinish"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="AttemptResultCode">
+  <suffix name="Success"/>
+  <suffix name="Failure"/>
+  <suffix name="Abandoned"/>
+  <suffix name="Retry"/>
+  <affected-histogram name="DefaultBrowser.AsyncSetAsDefault.Duration"/>

[nikunjb, 2015/10/26 17:45:30]

 include Other worker and LaunchFailure is skipped. Expected?

[Patrick Monette, 2015/10/26 18:10:21]

Yes because the duration for those error codes are not useful. If they even
happen, it will be at the beginning of setting the default browser and the
duration will always be 0.

+</histogram_suffixes>
+
 <histogram_suffixes name="AutofillDataAvailability" separator=".">
   <suffix name="WithNoData" label="no autofill data"/>
   <suffix name="WithOnlyServerData" label="only server autofill data"/>