WebFonts intervention: Add metrics only for miss-cached loading

third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp

Index: third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp
diff --git a/third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp b/third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp
index 0e092f1a8060ab6bd021738fee8308d5e0b68567..e74c4f98bf2e9a1594342e8fc88ad3968a6df790 100644
--- a/third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp
+++ b/third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp
@@ -24,33 +24,35 @@ namespace blink {
 
 namespace {
 
-    bool isEffectiveConnectionTypeSlowFor(Document* document)
-    {
-        WebEffectiveConnectionType type = document->frame()->loader().client()->getEffectiveConnectionType();
+bool isEffectiveConnectionTypeSlowFor(Document* document)
+{
+    WebEffectiveConnectionType type = document->frame()->loader().client()->getEffectiveConnectionType();
 
-        WebEffectiveConnectionType thresholdType = RuntimeEnabledFeatures::webFontsInterventionV2With2GEnabled()
-            ? WebEffectiveConnectionType::Type2G
-            : WebEffectiveConnectionType::TypeSlow2G;
+    WebEffectiveConnectionType thresholdType = RuntimeEnabledFeatures::webFontsInterventionV2With2GEnabled()
+        ? WebEffectiveConnectionType::Type2G
+        : WebEffectiveConnectionType::TypeSlow2G;
 
-        return WebEffectiveConnectionType::TypeOffline <= type && type <= thresholdType;
-    }
+    return WebEffectiveConnectionType::TypeOffline <= type && type <= thresholdType;
+}
 
-    bool isConnectionTypeSlow()
-    {
-        return networkStateNotifier().connectionType() == WebConnectionTypeCellular2G;
-    }
+bool isConnectionTypeSlow()
+{
+    return networkStateNotifier().connectionType() == WebConnectionTypeCellular2G;
+}
 
-    bool shouldTriggerWebFontsIntervention(Document* document, FontDisplay display)
-    {
-        if (RuntimeEnabledFeatures::webFontsInterventionTriggerEnabled())
-            return true;
+bool shouldTriggerWebFontsIntervention(Document* document, FontDisplay display, bool isLoadedFromMemoryCache)
+{
+    if (isLoadedFromMemoryCache)
+        return false;
+    if (RuntimeEnabledFeatures::webFontsInterventionTriggerEnabled())
+        return true;
 
-        bool isV2Enabled = RuntimeEnabledFeatures::webFontsInterventionV2With2GEnabled() || RuntimeEnabledFeatures::webFontsInterventionV2WithSlow2GEnabled();
+    bool isV2Enabled = RuntimeEnabledFeatures::webFontsInterventionV2With2GEnabled() || RuntimeEnabledFeatures::webFontsInterventionV2WithSlow2GEnabled();
 
-        bool networkIsSlow = isV2Enabled ? isEffectiveConnectionTypeSlowFor(document) : isConnectionTypeSlow();
+    bool networkIsSlow = isV2Enabled ? isEffectiveConnectionTypeSlowFor(document) : isConnectionTypeSlow();
 
-        return networkIsSlow && display == FontDisplayAuto;
-    }
+    return networkIsSlow && display == FontDisplayAuto;
+}
 
 } // namespace
 
@@ -60,11 +62,12 @@ RemoteFontFaceSource::RemoteFontFaceSource(FontResource* font, CSSFontSelector*
     , m_display(display)
     , m_period(display == FontDisplaySwap ? SwapPeriod : BlockPeriod)
     , m_isInterventionTriggered(false)
+    , m_isLoadedFromMemoryCache(font->isLoaded())
 {
     ThreadState::current()->registerPreFinalizer(this);
     m_font->addClient(this);
 
-    if (shouldTriggerWebFontsIntervention(m_fontSelector->document(), display)) {
+    if (shouldTriggerWebFontsIntervention(m_fontSelector->document(), display, m_isLoadedFromMemoryCache)) {
 
         m_isInterventionTriggered = true;
         m_period = SwapPeriod;
@@ -114,7 +117,7 @@ bool RemoteFontFaceSource::isValid() const
 void RemoteFontFaceSource::notifyFinished(Resource*)
 {
     m_histograms.recordRemoteFont(m_font.get());
-    m_histograms.fontLoaded(m_isInterventionTriggered);
+    m_histograms.fontLoaded(m_isInterventionTriggered, m_isLoadedFromMemoryCache || m_font->response().wasCached());
 
     m_font->ensureCustomFontData();
     // FIXME: Provide more useful message such as OTS rejection reason.
@@ -235,16 +238,16 @@ void RemoteFontFaceSource::FontLoadHistograms::fallbackFontPainted(DisplayPeriod
         m_blankPaintTime = currentTimeMS();
 }
 
-void RemoteFontFaceSource::FontLoadHistograms::fontLoaded(bool isInterventionTriggered)
+void RemoteFontFaceSource::FontLoadHistograms::fontLoaded(bool isInterventionTriggered, bool isLoadedFromCache)
 {
     if (!m_isLongLimitExceeded)
-        recordInterventionResult(isInterventionTriggered);
+        recordInterventionResult(isInterventionTriggered, isLoadedFromCache);
 }
 
 void RemoteFontFaceSource::FontLoadHistograms::longLimitExceeded(bool isInterventionTriggered)
 {
     m_isLongLimitExceeded = true;
-    recordInterventionResult(isInterventionTriggered);
+    recordInterventionResult(isInterventionTriggered, false);
 }
 
 void RemoteFontFaceSource::FontLoadHistograms::recordFallbackTime(const FontResource* font)
@@ -311,18 +314,21 @@ void RemoteFontFaceSource::FontLoadHistograms::recordLoadTimeHistogram(const Fon
     over1mbHistogram.count(duration);
 }
 
-void RemoteFontFaceSource::FontLoadHistograms::recordInterventionResult(bool triggered)
+void RemoteFontFaceSource::FontLoadHistograms::recordInterventionResult(bool isTriggered, bool isLoadedFromCache)
 {
     // interventionResult takes 0-3 values.
     int interventionResult = 0;
     if (m_isLongLimitExceeded)
         interventionResult |= 1 << 0;
-    if (triggered)
+    if (isTriggered)
         interventionResult |= 1 << 1;
     const int boundary = 1 << 2;
 
     DEFINE_STATIC_LOCAL(EnumerationHistogram, interventionHistogram, ("WebFont.InterventionResult", boundary));
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, missCachedInterventionHistogram, ("WebFont.MissCachedInterventionResult", boundary));
     interventionHistogram.count(interventionResult);
+    if (!isLoadedFromCache)
+        missCachedInterventionHistogram.count(interventionResult);
 }
 
 } // namespace blink