Deprecate ECT histogram and extend date for CC-NoTransform one

Bug: 1144811,1144812
Change-Id: I3b28456a40e9d553cff5c0ad85532a520fa1d2f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2512523Reviewed-by: Michael Crouse <mcrouse@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Sophie Chang <sophiechang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823290}

chrome/browser/previews/previews_content_util.cc

@@ -116,18 +116,6 @@ blink::PreviewsState DetermineAllowedClientPreviewsState(
   return previews_state;
 }
 
-void LogCommittedPreview(previews::PreviewsUserData* previews_data,
-                         PreviewsType type) {
-  net::EffectiveConnectionType navigation_ect = previews_data->navigation_ect();
-  UMA_HISTOGRAM_ENUMERATION("Previews.Triggered.EffectiveConnectionType2",
-                            navigation_ect,
-                            net::EFFECTIVE_CONNECTION_TYPE_LAST);
-  base::UmaHistogramEnumeration(
-      base::StringPrintf("Previews.Triggered.EffectiveConnectionType2.%s",
-                         GetStringNameForType(type).c_str()),
-      navigation_ect, net::EFFECTIVE_CONNECTION_TYPE_LAST);
-}
-
 // Records the result of the coin flip in PreviewsUserData and UKM. This may be
 // called multiple times during a navigation (like on redirects), but once
 // called with one |result|, that value is not expected to change.
@@ -259,7 +247,6 @@ blink::PreviewsState DetermineCommittedClientPreviewsState(
     if (previews_decider && previews_decider->ShouldCommitPreview(
                                 previews_data, navigation_handle,
                                 previews::PreviewsType::DEFER_ALL_SCRIPT)) {
-      LogCommittedPreview(previews_data, PreviewsType::DEFER_ALL_SCRIPT);
       return blink::PreviewsTypes::DEFER_ALL_SCRIPT_ON;
     }
     // Remove DEFER_ALL_SCRIPT_ON from |previews_state| since we decided not to
@@ -275,7 +262,6 @@ blink::PreviewsState DetermineCommittedClientPreviewsState(
         previews_decider->ShouldCommitPreview(
             previews_data, navigation_handle,
             previews::PreviewsType::RESOURCE_LOADING_HINTS)) {
-      LogCommittedPreview(previews_data, PreviewsType::RESOURCE_LOADING_HINTS);
       return blink::PreviewsTypes::RESOURCE_LOADING_HINTS_ON;
     }
     // Remove RESOURCE_LOADING_HINTS_ON from |previews_state| since we decided
@@ -290,7 +276,6 @@ blink::PreviewsState DetermineCommittedClientPreviewsState(
     if (previews_decider && previews_decider->ShouldCommitPreview(
                                 previews_data, navigation_handle,
                                 previews::PreviewsType::NOSCRIPT)) {
-      LogCommittedPreview(previews_data, PreviewsType::NOSCRIPT);
       return blink::PreviewsTypes::NOSCRIPT_ON;
     }
     // Remove NOSCRIPT_ON from |previews_state| since we decided not to

chrome/browser/previews/previews_content_util_unittest.cc

@@ -255,7 +255,6 @@ TEST_F(PreviewsContentUtilTest, DetermineCommittedClientPreviewsState) {
       std::string());
   PreviewsUserData user_data(1);
   user_data.set_navigation_ect(net::EFFECTIVE_CONNECTION_TYPE_SLOW_2G);
-  base::HistogramTester histogram_tester;
 
   // DeferAllScript has precedence over NoScript and ResourceLoadingHints.
   EXPECT_EQ(blink::PreviewsTypes::DEFER_ALL_SCRIPT_ON,
@@ -265,11 +264,6 @@ TEST_F(PreviewsContentUtilTest, DetermineCommittedClientPreviewsState) {
                     blink::PreviewsTypes::NOSCRIPT_ON |
                     blink::PreviewsTypes::RESOURCE_LOADING_HINTS_ON,
                 enabled_previews_decider(), nullptr));
-  histogram_tester.ExpectBucketCount(
-      "Previews.Triggered.EffectiveConnectionType2.DeferAllScript",
-      static_cast<int>(net::EFFECTIVE_CONNECTION_TYPE_SLOW_2G), 1);
-  histogram_tester.ExpectTotalCount(
-      "Previews.Triggered.EffectiveConnectionType2", 1);
 
   // RESOURCE_LOADING_HINTS has precedence over NoScript.
   EXPECT_EQ(blink::PreviewsTypes::RESOURCE_LOADING_HINTS_ON,
@@ -278,11 +272,6 @@ TEST_F(PreviewsContentUtilTest, DetermineCommittedClientPreviewsState) {
                 blink::PreviewsTypes::NOSCRIPT_ON |
                     blink::PreviewsTypes::RESOURCE_LOADING_HINTS_ON,
                 enabled_previews_decider(), nullptr));
-  histogram_tester.ExpectBucketCount(
-      "Previews.Triggered.EffectiveConnectionType2.ResourceLoadingHints",
-      static_cast<int>(net::EFFECTIVE_CONNECTION_TYPE_SLOW_2G), 1);
-  histogram_tester.ExpectTotalCount(
-      "Previews.Triggered.EffectiveConnectionType2", 2);
 
   // Only NoScript:
   EXPECT_EQ(blink::PreviewsTypes::NOSCRIPT_ON,
@@ -299,7 +288,6 @@ TEST_F(PreviewsContentUtilTest, DetermineCommittedClientPreviewsStateForHttp) {
       std::string());
   PreviewsUserData user_data(1);
   user_data.set_navigation_ect(net::EFFECTIVE_CONNECTION_TYPE_2G);
-  base::HistogramTester histogram_tester;
 
   // Verify that these previews do now commit on HTTP.
   EXPECT_EQ(blink::PreviewsTypes::DEFER_ALL_SCRIPT_ON,
@@ -309,8 +297,6 @@ TEST_F(PreviewsContentUtilTest, DetermineCommittedClientPreviewsStateForHttp) {
                     blink::PreviewsTypes::RESOURCE_LOADING_HINTS_ON |
                     blink::PreviewsTypes::DEFER_ALL_SCRIPT_ON,
                 enabled_previews_decider(), nullptr));
-  histogram_tester.ExpectTotalCount(
-      "Previews.Triggered.EffectiveConnectionType2", 1);
 
   EXPECT_EQ(blink::PreviewsTypes::RESOURCE_LOADING_HINTS_ON,
             previews::DetermineCommittedClientPreviewsState(

tools/metrics/histograms/histograms_xml/others/histograms.xml

@@ -10552,10 +10552,10 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Previews.CacheControlNoTransform.BlockedPreview"
-    enum="PreviewsType" expires_after="2020-12-12">
-  <owner>dougarnett@chromium.org</owner>
+    enum="PreviewsType" expires_after="2021-03-31">
+  <owner>sophiechang@chromium.org</owner>
   <owner>mcrouse@chromium.org</owner>
-  <owner>src/components/data_reduction_proxy/OWNERS</owner>
+  <owner>src/components/previews/OWNERS</owner>
   <summary>
     Blocked previews due to Cache-Control:no-transform directive.
   </summary>
@@ -10696,9 +10696,12 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Previews.Triggered.EffectiveConnectionType2"
     enum="NQEEffectiveConnectionType" expires_after="2020-12-12">
+  <obsolete>
+    Obsolete as of 11/2020.
+  </obsolete>
   <owner>dougarnett@chromium.org</owner>
   <owner>mcrouse@chromium.org</owner>
-  <owner>src/components/data_reduction_proxy/OWNERS</owner>
+  <owner>src/components/previews/OWNERS</owner>
   <summary>
     Records the effective connection type of a navigation that triggers a
     preview. This is captured at commit time but uses the effective connection