Adding a destination platform histogram for UMA.

chrome/browser/chromeos/arc/intent_helper/arc_external_protocol_dialog.cc

Index: chrome/browser/chromeos/arc/intent_helper/arc_external_protocol_dialog.cc
diff --git a/chrome/browser/chromeos/arc/intent_helper/arc_external_protocol_dialog.cc b/chrome/browser/chromeos/arc/intent_helper/arc_external_protocol_dialog.cc
index f49f39f6e5b238741031a5bb3addcbba703ad0c2..a204e3ab4138e33fdef350bd2d727637a4f4e576 100644
--- a/chrome/browser/chromeos/arc/intent_helper/arc_external_protocol_dialog.cc
+++ b/chrome/browser/chromeos/arc/intent_helper/arc_external_protocol_dialog.cc
@@ -40,10 +40,15 @@ constexpr uint32_t kMinVersionForHandleUrl = 2;
 constexpr uint32_t kMinVersionForRequestUrlHandlerList = 2;
 constexpr uint32_t kMinVersionForAddPreferredPackage = 7;
 
-void RecordUma(ArcNavigationThrottle::CloseReason close_reason) {
+void RecordUma(ArcNavigationThrottle::CloseReason close_reason,
+               ArcNavigationThrottle::Platform platform) {
   UMA_HISTOGRAM_ENUMERATION(
       "Arc.IntentHandlerAction", static_cast<int>(close_reason),
       static_cast<int>(ArcNavigationThrottle::CloseReason::SIZE));
+
+  UMA_HISTOGRAM_ENUMERATION(
+      "Arc.IntentHandlerSelectedPlatform", static_cast<int>(platform),

[elijahtaylor1, 2016/11/03 22:22:00]

nit: calling it Selected (here and elsewhere) seems like there was a user
action, which isn't always the case.  This is why I called it Destination or
something like that in the bug

[djacobo_, 2016/11/03 23:13:55]

Makes sense. Done.

+      static_cast<int>(ArcNavigationThrottle::Platform::SIZE));
 }
 
 // Shows the Chrome OS' original external protocol dialog as a fallback.
@@ -271,7 +276,11 @@ void OnIntentPickerClosed(int render_process_host_id,
       break;
     }
   }
-  RecordUma(close_reason);
+
+  ArcNavigationThrottle::Platform platform =
+      ArcNavigationThrottle::GetSelectedPlatform(selected_app_package,
+                                                 close_reason);
+  RecordUma(close_reason, platform);
 }
 
 // Called when ARC returned activity icons for the |handlers|.
@@ -324,8 +333,10 @@ void OnUrlHandlerList(int render_process_host_id,
   GetActionResult result;
   if (HandleUrl(render_process_host_id, routing_id, url, handlers,
                 handlers.size(), &result)) {
-    if (result == GetActionResult::HANDLE_URL_IN_ARC)
-      RecordUma(ArcNavigationThrottle::CloseReason::PREFERRED_ACTIVITY_FOUND);
+    RecordUma(ArcNavigationThrottle::CloseReason::PREFERRED_ACTIVITY_FOUND,

[djacobo_, 2016/11/03 22:11:54]

I assumed we would like to track as PREFERRED also under the OPEN_URL_IN_CHROME
option.

[elijahtaylor1, 2016/11/03 22:22:00]

Ah, this is interesting that we were only setting this on ARC navigation.

I agree we probably want to have this recorded for both.

You probably should put a note in the histograms.xml file for this histogram
that we changed the nature of this in M56 so we know how to interpret the values
in different milestones.

[djacobo_, 2016/11/03 23:13:55]

Alright, let me add a comment in the related histogram

+              result == GetActionResult::HANDLE_URL_IN_ARC
+                  ? ArcNavigationThrottle::Platform::ARC
+                  : ArcNavigationThrottle::Platform::CHROME);
     return;  // the |url| has been handled.
   }