Mute use counters for internal pages

third_party/WebKit/Source/core/frame/UseCounter.cpp

Index: third_party/WebKit/Source/core/frame/UseCounter.cpp
diff --git a/third_party/WebKit/Source/core/frame/UseCounter.cpp b/third_party/WebKit/Source/core/frame/UseCounter.cpp
index 383f0723f01a99f0ed9db84c091198423fa87d0e..e8526fef78236ac52f0b6bda569dfcb4aabd7818 100644
--- a/third_party/WebKit/Source/core/frame/UseCounter.cpp
+++ b/third_party/WebKit/Source/core/frame/UseCounter.cpp
@@ -37,6 +37,7 @@
 #include "core/workers/WorkerOrWorkletGlobalScope.h"
 #include "platform/Histogram.h"
 #include "platform/instrumentation/tracing/TraceEvent.h"
+#include "platform/weborigin/SchemeRegistry.h"
 
 namespace {
 
@@ -1083,6 +1084,7 @@ int UseCounter::mapCSSPropertyIdToCSSSampleIdForHistogram(
 
 UseCounter::UseCounter(Context context)
     : m_muteCount(0),
+      m_disableReporting(false),
       m_context(context),
       m_featuresRecorded(NumberOfFeatures),
       m_CSSRecorded(lastUnresolvedCSSProperty + 1) {}
@@ -1107,9 +1109,11 @@ void UseCounter::recordMeasurement(Feature feature) {
   if (!m_featuresRecorded.quickGet(feature)) {
     // Note that HTTPArchive tooling looks specifically for this event - see
     // https://github.com/HTTPArchive/httparchive/issues/59
-    TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("blink.feature_usage"),
-                 "FeatureFirstUsed", "feature", feature);
-    featuresHistogram().count(feature);
+    if (!m_disableReporting) {
+      TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("blink.feature_usage"),
+                   "FeatureFirstUsed", "feature", feature);
+      featuresHistogram().count(feature);
+    }
     m_featuresRecorded.quickSet(feature);
   }
   m_legacyCounter.countFeature(feature);
@@ -1127,14 +1131,26 @@ bool UseCounter::hasRecordedMeasurement(Feature feature) const {
   return m_featuresRecorded.quickGet(feature);
 }
 
-void UseCounter::didCommitLoad() {
+void UseCounter::didCommitLoad(KURL url) {
   m_legacyCounter.updateMeasurements();
 
-  // TODO: Is didCommitLoad really the right time to do this?  crbug.com/608040
+  // Reset state from previous load.
+  m_disableReporting = false;
+
+  // Use the protocol of the document being loaded into the main frame to
+  // decide whether this page is interesting from a metrics perspective.
+  // Note that SVGImage cases always have an about:blank URL
+  if (m_context == DefaultContext &&
+      !SchemeRegistry::shouldTrackUsageMetricsForScheme(url.protocol())) {
+    m_disableReporting = true;
+  }
+
   m_featuresRecorded.clearAll();
-  featuresHistogram().count(PageVisits);
   m_CSSRecorded.clearAll();
-  cssHistogram().count(totalPagesMeasuredCSSSampleId());
+  if (!m_disableReporting && !m_muteCount) {
+    featuresHistogram().count(PageVisits);
+    cssHistogram().count(totalPagesMeasuredCSSSampleId());
+  }
 }
 
 void UseCounter::count(const Frame* frame, Feature feature) {
@@ -1207,9 +1223,11 @@ void UseCounter::count(CSSParserMode cssParserMode, CSSPropertyID property) {
     // Note that HTTPArchive tooling looks specifically for this event - see
     // https://github.com/HTTPArchive/httparchive/issues/59
     int sampleId = mapCSSPropertyIdToCSSSampleIdForHistogram(property);
-    TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("blink.feature_usage"),
-                 "CSSFirstUsed", "feature", sampleId);
-    cssHistogram().count(sampleId);
+    if (!m_disableReporting) {
+      TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("blink.feature_usage"),
+                   "CSSFirstUsed", "feature", sampleId);
+      cssHistogram().count(sampleId);
+    }
     m_CSSRecorded.quickSet(property);
   }
   m_legacyCounter.countCSS(property);
@@ -1241,10 +1259,12 @@ UseCounter* UseCounter::getFrom(const StyleSheetContents* sheetContents) {
 }
 
 EnumerationHistogram& UseCounter::featuresHistogram() const {
-  // TODO(rbyers): Fix the SVG case.  crbug.com/236262
-  // Eg. every SVGImage has it's own Page instance, they should probably all be
-  // delegating their UseCounter to the containing Page.  For now just use a
-  // separate histogram.
+  // Every SVGImage has it's own Page instance, and multiple web pages can
+  // share the usage of a single SVGImage.  Ideally perhaps we'd delegate
+  // metrics from an SVGImage to one of the Page's it's displayed in, but
+  // that's tricky (SVGImage is intentionally isolated, and the Page that
+  // created it may not even exist anymore).
+  // So instead we just use a dedicated histogram for the SVG case.
   DEFINE_STATIC_LOCAL(blink::EnumerationHistogram, histogram,
                       ("WebCore.UseCounter_TEST.Features",
                        blink::UseCounter::NumberOfFeatures));