[WIP] WebFonts cache-aware timeout adaption

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 0d5f323799f2cf30939d9da36dda534df5e8b7d5..21b07dc825f1ed0424d5dbebe16701d490691d1b 100644
--- a/third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp
+++ b/third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp
@@ -56,7 +56,7 @@ RemoteFontFaceSource::RemoteFontFaceSource(FontResource* font,
     : 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
@@ -73,6 +73,10 @@ RemoteFontFaceSource::RemoteFontFaceSource(FontResource* font,
         "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() {}
@@ -158,6 +162,11 @@ void RemoteFontFaceSource::fontLoadLongLimitExceeded(FontResource*) {
   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;
@@ -234,7 +243,15 @@ PassRefPtr<SimpleFontData> RemoteFontFaceSource::createLoadingFallbackFontData(
 
 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();