Removing a histogram that we no longer need, OffliningPreviewStatus

Bug: 1165265
Change-Id: Id6a236cda259920b1e1069ebfaac646e68ed364f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2644057Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Carlos Knippschild <carlosk@chromium.org>
Commit-Queue: Peter Williamson <petewil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#846359}

chrome/browser/offline_pages/background_loader_offliner.cc

@@ -65,18 +65,6 @@ void RecordErrorCauseUMA(const ClientId& client_id, int error_code) {
       error_code);
 }
 
-void RecordOffliningPreviewsUMA(const ClientId& client_id,
-                                blink::PreviewsState previews_state) {
-  bool is_previews_enabled =
-      (previews_state != blink::PreviewsTypes::PREVIEWS_OFF &&
-       previews_state != blink::PreviewsTypes::PREVIEWS_NO_TRANSFORM);
-
-  base::UmaHistogramBoolean(
-      AddHistogramSuffix(client_id,
-                         "OfflinePages.Background.OffliningPreviewStatus"),
-      is_previews_enabled);
-}
-
 void HandleLoadTerminationCancel(
     Offliner::CompletionCallback completion_callback,
     const SavePageRequest& canceled_request) {
@@ -339,7 +327,6 @@ void BackgroundLoaderOffliner::DidFinishNavigation(
       previews_state = previews_user_data->CommittedPreviewsState();
   }
 
-  RecordOffliningPreviewsUMA(pending_request_->client_id(), previews_state);
 }
 
 void BackgroundLoaderOffliner::SetBackgroundSnapshotControllerForTest(

chrome/browser/offline_pages/background_loader_offliner_unittest.cc

@@ -817,64 +817,6 @@ TEST_F(BackgroundLoaderOfflinerTest, DoesNotCrashWithNullResponseHeaders) {
   offliner()->DidFinishNavigation(&handle);
 }
 
-TEST_F(BackgroundLoaderOfflinerTest, OffliningPreviewsStatusOffHistogram) {
-  base::Time creation_time = base::Time::Now();
-  SavePageRequest request(kRequestId, HttpUrl(), kClientId, creation_time,
-                          kUserRequested);
-  EXPECT_TRUE(offliner()->LoadAndSave(request, completion_callback(),
-                                      progress_callback()));
-
-  // Called after calling LoadAndSave so we have web_contents to work with.
-  content::MockNavigationHandle handle(
-      HttpUrl(), offliner()->web_contents()->GetMainFrame());
-  handle.set_has_committed(true);
-  // Set up PreviewsUserData on the handle.
-  PreviewsUITabHelper::CreateForWebContents(offliner()->web_contents());
-  PreviewsUITabHelper::FromWebContents(offliner()->web_contents())
-      ->CreatePreviewsUserDataForNavigationHandle(&handle, 1u)
-      ->set_committed_previews_state(
-          blink::PreviewsTypes::PREVIEWS_NO_TRANSFORM);
-  scoped_refptr<net::HttpResponseHeaders> header(
-      new net::HttpResponseHeaders("HTTP/1.1 200 OK"));
-  handle.set_response_headers(header.get());
-  // Call DidFinishNavigation with handle.
-  offliner()->DidFinishNavigation(&handle);
-
-  histograms().ExpectBucketCount(
-      "OfflinePages.Background.OffliningPreviewStatus.async_loading",
-      0,  // Previews Disabled
-      1);
-}
-
-TEST_F(BackgroundLoaderOfflinerTest, OffliningPreviewsStatusOnHistogram) {
-  base::Time creation_time = base::Time::Now();
-  SavePageRequest request(kRequestId, HttpUrl(), kClientId, creation_time,
-                          kUserRequested);
-  EXPECT_TRUE(offliner()->LoadAndSave(request, completion_callback(),
-                                      progress_callback()));
-
-  // Called after calling LoadAndSave so we have web_contents to work with.
-  content::MockNavigationHandle handle(
-      HttpUrl(), offliner()->web_contents()->GetMainFrame());
-  handle.set_has_committed(true);
-  // Set up PreviewsUserData on the handle.
-  PreviewsUITabHelper::CreateForWebContents(offliner()->web_contents());
-  PreviewsUITabHelper::FromWebContents(offliner()->web_contents())
-      ->CreatePreviewsUserDataForNavigationHandle(&handle, 1u)
-      ->set_committed_previews_state(blink::PreviewsTypes::DEFER_ALL_SCRIPT_ON);
-  scoped_refptr<net::HttpResponseHeaders> header(
-      new net::HttpResponseHeaders("HTTP/1.1 200 OK"));
-  handle.set_response_headers(header.get());
-
-  // Call DidFinishNavigation with handle.
-  offliner()->DidFinishNavigation(&handle);
-
-  histograms().ExpectBucketCount(
-      "OfflinePages.Background.OffliningPreviewStatus.async_loading",
-      1,  // Previews Enabled
-      1);
-}
-
 TEST_F(BackgroundLoaderOfflinerTest, OnlySavesOnceOnMultipleLoads) {
   base::Time creation_time = base::Time::Now();
   SavePageRequest request(kRequestId, HttpUrl(), kClientId, creation_time,

tools/metrics/histograms/histograms_xml/offline/histograms.xml

@@ -309,6 +309,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="OfflinePages.Background.OffliningPreviewStatus"
     enum="BooleanEnabled" expires_after="2021-01-25">
+  <obsolete>
+    Removed 22 Jan 2021.
+  </obsolete>
   <owner>petewil@chromium.org</owner>
   <owner>offline-dev@chromium.org</owner>
   <summary>