Collect data on site engagement vs dialogs.

chrome/browser/ui/javascript_dialogs/javascript_dialog_tab_helper.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #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);
 
 namespace {
 
 const base::Feature kAutoDismissingDialogsFeature{
     "AutoDismissingDialogs", base::FEATURE_DISABLED_BY_DEFAULT};
 
 bool IsEnabled() {
@@ skipping 18 matching lines @@
 }
 
 void JavaScriptDialogTabHelper::RunJavaScriptDialog(
     content::WebContents* web_contents,
     const GURL& origin_url,
     content::JavaScriptMessageType message_type,
     const base::string16& message_text,
     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
   // - they can be requested for many tabs at the same time
   // and therefore auto-dismissal is inappropriate for them.
 
   return AppModalDialogManager()->RunBeforeUnloadDialog(web_contents, is_reload,
                                                         callback);
 }
 
@@ skipping 19 matching lines @@
 }
 
 void JavaScriptDialogTabHelper::ResetDialogState(
     content::WebContents* web_contents) {
   // Reset any app-modal dialog state that may exist.
   if (!IsEnabled())
     return AppModalDialogManager()->ResetDialogState(web_contents);
 
   // More work here for the auto-dismissing dialogs.
 }