Remove unused Chrome histograms Blink.UseCounter.SVGImage.*CSS*

Bug: 804645
Change-Id: I19e29e9d201eea3d6bd9e8a42f6e0621672ae2aa
Reviewed-on: https://chromium-review.googlesource.com/1100972Reviewed-by: Rick Byers <rbyers@chromium.org>
Commit-Queue: Luna Lu <loonybear@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567642}

third_party/blink/renderer/core/frame/use_counter.cc

@@ -1298,17 +1298,11 @@ void UseCounter::DidCommitLoad(const LocalFrame* frame) {
   css_recorded_.ClearAll();
   animated_css_recorded_.ClearAll();
 
-  if (context_ != kDisabledContext && !mute_count_) {
-    // Only needs to count page visits on SVG histogram and extension histogram
-    // since the features histogram is being recorded on the browser side.
-    if (context_ != kDefaultContext)
+  // TODO(loonybear): Remove or move SVG features histogram and extension
+  // features histogram to the browser side.
+  if (!mute_count_ &&
+      (context_ == kSVGImageContext || context_ == kExtensionContext))
     FeaturesHistogram().Count(static_cast<int>(WebFeature::kPageVisits));
-    if (context_ == kSVGImageContext) {
-      CssHistogram().Count(mojom::blink::kTotalPagesMeasuredCSSSampleId);
-      AnimatedCSSHistogram().Count(
-          mojom::blink::kTotalPagesMeasuredCSSSampleId);
-    }
-  }
 }
 
 void UseCounter::Count(const LocalFrame* frame, WebFeature feature) {
@@ -1379,13 +1373,6 @@ void UseCounter::Count(CSSParserMode css_parser_mode,
   if (!IsUseCounterEnabledForMode(css_parser_mode) || mute_count_)
     return;
 
-  // TODO(loonybear): Remove this check once UseCounter is moved from Page to
-  // DocumentLoader. No features would be counted before
-  // UseCounter::DidCommitLoad (crbug.com/828416).
-  if (context_ == kDefaultContext &&
-      !Page::OrdinaryPages().Contains(source_frame->GetPage()))
-    return;
-
   if (!css_recorded_.QuickGet(property)) {
     // Note that HTTPArchive tooling looks specifically for this event - see
     // https://github.com/HTTPArchive/httparchive/issues/59
@@ -1393,11 +1380,6 @@ void UseCounter::Count(CSSParserMode css_parser_mode,
     if (context_ != kDisabledContext && context_ != kExtensionContext) {
       TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("blink.feature_usage"),
                    "CSSFirstUsed", "feature", sample_id);
-      // The CSS properties are being recorded on the browser side.
-      // TODO(loonybear): Record CSS properties for SVG documents on the browser
-      // side.
-      if (context_ == kSVGImageContext)
-        CssHistogram().Count(sample_id);
       if (source_frame && source_frame->Client())
         source_frame->Client()->DidObserveNewCssPropertyUsage(sample_id, false);
     }
@@ -1441,23 +1423,11 @@ void UseCounter::CountAnimatedCSS(CSSPropertyID property,
   if (mute_count_)
     return;
 
-  // TODO(loonybear): Remove this check once UseCounter is moved from Page to
-  // DocumentLoader. No features would be counted before
-  // UseCounter::DidCommitLoad (crbug.com/828416).
-  if (context_ == kDefaultContext &&
-      !Page::OrdinaryPages().Contains(source_frame->GetPage()))
-    return;
-
   if (!animated_css_recorded_.QuickGet(property)) {
     int sample_id = MapCSSPropertyIdToCSSSampleIdForHistogram(property);
     if (context_ != kDisabledContext && context_ != kExtensionContext) {
       TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("blink.feature_usage"),
                    "AnimatedCSSFirstUsed", "feature", sample_id);
-      // The CSS properties are being recorded on the browser side.
-      // TODO(loonybear): Record CSS properties for SVG documents on the browser
-      // side.
-      if (context_ == kSVGImageContext)
-        AnimatedCSSHistogram().Count(sample_id);
       if (source_frame && source_frame->Client())
         source_frame->Client()->DidObserveNewCssPropertyUsage(sample_id, true);
     }

third_party/blink/renderer/core/frame/use_counter_test.cc

@@ -20,13 +20,6 @@ const char kExtensionFeaturesHistogramName[] =
     "Blink.UseCounter.Extensions.Features";
 
 const char kSVGFeaturesHistogramName[] = "Blink.UseCounter.SVGImage.Features";
-const char kSVGCSSHistogramName[] = "Blink.UseCounter.SVGImage.CSSProperties";
-const char kSVGAnimatedCSSHistogramName[] =
-    "Blink.UseCounter.SVGImage.AnimatedCSSProperties";
-
-const char* kHistogramList[] = {kExtensionFeaturesHistogramName,
-                                kSVGCSSHistogramName,
-                                kSVGAnimatedCSSHistogramName};
 
 // In practice, SVGs always appear to be loaded with an about:blank URL
 const char kSvgUrl[] = "about:blank";
@@ -114,31 +107,6 @@ void UseCounterTest::HistogramBasicTest(
   EXPECT_TRUE(counted(item));
   histogram_tester_.ExpectBucketCount(histogram, histogram_map(item), 2);
   histogram_tester_.ExpectTotalCount(histogram, 4);
-
-  // For all histograms, no other histograms besides |histogram| should
-  // be affected.
-  for (const std::string& unaffected_histogram : kHistogramList) {
-    if (unaffected_histogram == histogram)
-      continue;
-    // CSS histograms are never created in didCommitLoad when the context is
-    // extension.
-    if (histogram == kExtensionFeaturesHistogramName &&
-        unaffected_histogram.find("CSS") != std::string::npos)
-      continue;
-
-    // The expected total count for "Features" of unaffected histograms should
-    // be either:
-    //    a. pageVisits, for "CSSProperties"; or
-    //    b. 0 (pageVisits is 0), for others, including "SVGImage.CSSProperties"
-    //      since no SVG images are loaded at all.
-    histogram_tester_.ExpectTotalCount(
-        unaffected_histogram,
-        unaffected_histogram.find("CSS") != std::string::npos
-            ? histogram_tester_.GetBucketCount(
-                  unaffected_histogram,
-                  GetPageVisitsBucketforHistogram(unaffected_histogram))
-            : 0);
-  }
 }
 
 TEST_F(UseCounterTest, RecordingExtensions) {
@@ -172,38 +140,6 @@ TEST_F(UseCounterTest, SVGImageContextFeatures) {
       [&](LocalFrame* frame) { use_counter.DidCommitLoad(frame); }, kSvgUrl);
 }
 
-TEST_F(UseCounterTest, SVGImageContextCSSProperties) {
-  UseCounter use_counter(UseCounter::kSVGImageContext);
-  HistogramBasicTest<CSSPropertyID>(
-      kSVGCSSHistogramName, CSSPropertyFont, CSSPropertyZoom,
-      [&](CSSPropertyID property) -> bool {
-        return use_counter.IsCounted(property);
-      },
-      [&](CSSPropertyID property) {
-        use_counter.Count(kHTMLStandardMode, property, GetFrame());
-      },
-      [](CSSPropertyID property) -> int {
-        return UseCounter::MapCSSPropertyIdToCSSSampleIdForHistogram(property);
-      },
-      [&](LocalFrame* frame) { use_counter.DidCommitLoad(frame); }, kSvgUrl);
-}
-
-TEST_F(UseCounterTest, SVGImageContextAnimatedCSSProperties) {
-  UseCounter use_counter(UseCounter::kSVGImageContext);
-  HistogramBasicTest<CSSPropertyID>(
-      kSVGAnimatedCSSHistogramName, CSSPropertyOpacity, CSSPropertyVariable,
-      [&](CSSPropertyID property) -> bool {
-        return use_counter.IsCountedAnimatedCSS(property);
-      },
-      [&](CSSPropertyID property) {
-        use_counter.CountAnimatedCSS(property, GetFrame());
-      },
-      [](CSSPropertyID property) -> int {
-        return UseCounter::MapCSSPropertyIdToCSSSampleIdForHistogram(property);
-      },
-      [&](LocalFrame* frame) { use_counter.DidCommitLoad(frame); }, kSvgUrl);
-}
-
 TEST_F(UseCounterTest, CSSSelectorPseudoIS) {
   std::unique_ptr<DummyPageHolder> dummy_page_holder =
       DummyPageHolder::Create(IntSize(800, 600));