[WIP] WebFonts cache-aware timeout adaption

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/RemoteFontFaceSource.h"
 
 #include "core/css/CSSCustomFontData.h"
 #include "core/css/CSSFontFace.h"
 #include "core/css/CSSFontSelector.h"
 #include "core/dom/Document.h"
@@ skipping 38 matching lines @@
 }
 
 }  // namespace
 
 RemoteFontFaceSource::RemoteFontFaceSource(FontResource* font,
                                            CSSFontSelector* fontSelector,
                                            FontDisplay display)
     : m_font(font),
       m_fontSelector(fontSelector),
       m_display(display),
-      m_period(display == FontDisplaySwap ? SwapPeriod : BlockPeriod),
+      m_period(BlockPeriod),
       m_histograms(font->url().protocolIsData()
                        ? FontLoadHistograms::FromDataURL
                        : font->isLoaded() ? FontLoadHistograms::FromMemoryCache
                                           : FontLoadHistograms::FromUnknown),
       m_isInterventionTriggered(false) {
   ThreadState::current()->registerPreFinalizer(this);
   m_font->addClient(this);
 
   if (shouldTriggerWebFontsIntervention()) {
     m_isInterventionTriggered = true;
     m_period = SwapPeriod;
     m_fontSelector->document()->addConsoleMessage(ConsoleMessage::create(
         OtherMessageSource, InfoMessageLevel,
         "Slow network is detected. Fallback font will be used while loading: " +
             m_font->url().elidedString()));
   }
+
+  if (m_display == FontDisplaySwap &&
+      !m_font->resourceRequest().isCacheAwareLoadingActivated())
+    m_period = SwapPeriod;
 }
 
 RemoteFontFaceSource::~RemoteFontFaceSource() {}
 
 void RemoteFontFaceSource::dispose() {
   m_font->removeClient(this);
   m_font = nullptr;
   pruneTable();
 }
 
@@ skipping 65 matching lines @@
 
   if (m_display == FontDisplayBlock ||
       (!m_isInterventionTriggered && m_display == FontDisplayAuto))
     switchToSwapPeriod();
   else if (m_display == FontDisplayFallback)
     switchToFailurePeriod();
 
   m_histograms.longLimitExceeded(m_isInterventionTriggered);
 }
 
+void RemoteFontFaceSource::willReloadAfterDiskCacheMiss(const FontResource*) {
+  if (m_display == FontDisplaySwap)
+    switchToSwapPeriod();
+}
+
 void RemoteFontFaceSource::switchToSwapPeriod() {
   ASSERT(m_period == BlockPeriod);
   m_period = SwapPeriod;
 
   pruneTable();
   if (m_face) {
     m_fontSelector->fontFaceInvalidated();
     m_face->didBecomeVisibleFallback(this);
   }
 
@@ skipping 56 matching lines @@
     return nullptr;
   }
   RefPtr<CSSCustomFontData> cssFontData = CSSCustomFontData::create(
       this, m_period == BlockPeriod ? CSSCustomFontData::InvisibleFallback
                                     : CSSCustomFontData::VisibleFallback);
   return SimpleFontData::create(temporaryFont->platformData(), cssFontData);
 }
 
 void RemoteFontFaceSource::beginLoadIfNeeded() {
   if (m_fontSelector->document() && m_font->stillNeedsLoad()) {
+    // TODO(shaochuan): Cache-aware loading may be deactivated in startLoad(),
+    // set |m_period| to correct value if deactivated. crbug.com/632580
+    bool wasCacheAwareLoadingActivated =
+        m_font->resourceRequest().isCacheAwareLoadingActivated();
     m_fontSelector->document()->fetcher()->startLoad(m_font);
+    if (m_display == FontDisplaySwap && wasCacheAwareLoadingActivated &&
+        !m_font->resourceRequest().isCacheAwareLoadingActivated())
+      m_period = SwapPeriod;

[Kunihiko Sakamoto, 2016/10/21 05:41:07]

You should call switchToSwapPeriod() instead, so that blank text is replaced
with visible fallback font.

[Shao-Chuan Lee, 2016/10/21 07:18:01]

Done.

+
     if (!m_font->isLoaded())
       m_font->startLoadLimitTimers();
     m_histograms.loadStarted();
   }
 
   if (m_face)
     m_face->didBeginLoad();
 }
 
 DEFINE_TRACE(RemoteFontFaceSource) {
@@ skipping 176 matching lines @@
       return Miss;
     case FromUnknown:
     // Fall through.
     default:
       NOTREACHED();
   }
   return Miss;
 }
 
 }  // namespace blink