Collect data on site engagement vs dialogs.

chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc

Index: chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc
diff --git a/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc b/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc
index 86199c0a73b23835851d915851406c43bc56f667..a284efdabe2ee29dfa82d609d1d4612b625f40b4 100644
--- a/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc
+++ b/chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc
@@ -5,6 +5,9 @@
 #include "chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.h"
 
 #include "base/feature_list.h"
+#include "base/metrics/histogram_macros.h"
+#include "chrome/browser/engagement/site_engagement_service.h"
+#include "chrome/browser/profiles/profile.h"
 #include "components/app_modal/javascript_dialog_manager.h"
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(JavaScriptDialogTabHelper);
@@ -43,19 +46,62 @@ void JavaScriptDialogTabHelper::RunJavaScriptDialog(
     const base::string16& default_prompt_text,
     const DialogClosedCallback& callback,
     bool* did_suppress_message) {
-  if (!IsEnabled()) {
-    return AppModalDialogManager()->RunJavaScriptDialog(
+  Profile* profile =

[dominickn, 2016/09/06 23:50:29]

Minor nit - you could inline the Profile::FromBrowserContext() call into the
SiteEngagementService::Get call in both locations.

[Avi (use Gerrit), 2016/09/07 16:41:55]

Done.

+      Profile::FromBrowserContext(web_contents->GetBrowserContext());
+  SiteEngagementService* site_engagement_service =
+      SiteEngagementService::Get(profile);
+  UMA_HISTOGRAM_PERCENTAGE("JSDialogs.SiteKarmaOfDialogs",
+                           site_engagement_service->GetScore(origin_url));
+  int32_t message_length = static_cast<int32_t>(message_text.length());
+  switch (site_engagement_service->GetEngagementLevel(origin_url)) {
+    case SiteEngagementService::ENGAGEMENT_LEVEL_NONE: {

[dominickn, 2016/09/06 23:50:29]

I think it might be better to base these histograms on explicit constants rather
than levels - it's possible we tweak the levels in the future, and that would
make the data inconsistent.

Also, "LOW" Karma is currently regarded as <5 - and I think that's possibly too
high a boundary for gating dialogs. I would suggest an additional histogram for
<1 Karma:

CountOfCharactersKarmaNone -> 0 Karma
CountOfCharactersKarmaLessThanOne -> <1 Karma
CountOfCharactersKarmaOneToFive -> 1 <= Karma < 5
CountOfCharactersKarmaHigher -> >=5 Karma

[Avi (use Gerrit), 2016/09/07 16:41:55]

Done.

Also, is it OK to use "karma" as a term in UMA?

+      UMA_HISTOGRAM_COUNTS(
+          "JSDialogs.CountOfJSDialogMessageCharactersKarmaNone",
+          message_length);
+      break;
+    }
+
+    case SiteEngagementService::ENGAGEMENT_LEVEL_LOW: {
+      UMA_HISTOGRAM_COUNTS("JSDialogs.CountOfJSDialogMessageCharactersKarmaLow",
+                           message_length);
+      break;
+    }
+
+    default: {
+      UMA_HISTOGRAM_COUNTS(
+          "JSDialogs.CountOfJSDialogMessageCharactersKarmaHigher",
+          message_length);
+      break;
+    }
+  }
+
+  if (IsEnabled()) {
+    NOTREACHED() << "auto-dismissing dialog code does not yet exist";
+  } else {
+    AppModalDialogManager()->RunJavaScriptDialog(
         web_contents, origin_url, message_type, message_text,
         default_prompt_text, callback, did_suppress_message);
   }
 
-  NOTREACHED() << "auto-dismissing dialog code does not yet exist";
+  if (did_suppress_message) {
+    UMA_HISTOGRAM_COUNTS(
+        "JSDialogs.CountOfJSDialogMessageCharactersUserSuppressed",
+        message_length);
+  }
 }
 
 void JavaScriptDialogTabHelper::RunBeforeUnloadDialog(
     content::WebContents* web_contents,
     bool is_reload,
     const DialogClosedCallback& callback) {
+  Profile* profile =
+      Profile::FromBrowserContext(web_contents->GetBrowserContext());
+  SiteEngagementService* site_engagement_service =
+      SiteEngagementService::Get(profile);
+  UMA_HISTOGRAM_PERCENTAGE(
+      "JSDialogs.SiteKarmaOfBeforeUnload",
+      site_engagement_service->GetScore(web_contents->GetLastCommittedURL()));
+
   // onbeforeunload dialogs are always handled with an app-modal dialog, because
   // - they are critical to the user not losing data
   // - they can be requested for tabs that are not foremost