WebFonts cache-aware timeout adaptation

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 e6f9a8c7845dd7d7ec5e0fb09577a04afb6d853a..dc8bd927db8da26489066f8ae8820e353d71089f 100644
--- a/third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp
+++ b/third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp
@@ -9,6 +9,7 @@
 #include "core/css/CSSFontSelector.h"
 #include "core/dom/Document.h"
 #include "core/fetch/ResourceFetcher.h"
+#include "core/fetch/ResourceLoader.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "core/page/NetworkStateNotifier.h"
@@ -56,7 +57,7 @@ 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
@@ -161,8 +162,15 @@ void RemoteFontFaceSource::fontLoadLongLimitExceeded(FontResource*) {
   m_histograms.longLimitExceeded(m_isInterventionTriggered);
 }
 
+void RemoteFontFaceSource::willReloadAfterDiskCacheMiss(const FontResource*) {
+  DCHECK(m_font->isLoading());
+  DCHECK(m_font->loader()->isCacheAwareLoadingActivated());
+  if (m_display == FontDisplaySwap)
+    switchToSwapPeriod();
+}
+
 void RemoteFontFaceSource::switchToSwapPeriod() {
-  ASSERT(m_period == BlockPeriod);
+  DCHECK_EQ(m_period, BlockPeriod);
   m_period = SwapPeriod;
 
   pruneTable();
@@ -177,7 +185,7 @@ void RemoteFontFaceSource::switchToSwapPeriod() {
 void RemoteFontFaceSource::switchToFailurePeriod() {
   if (m_period == BlockPeriod)
     switchToSwapPeriod();
-  ASSERT(m_period == SwapPeriod);
+  DCHECK_EQ(m_period, SwapPeriod);
   m_period = FailurePeriod;
 }
 
@@ -243,6 +251,15 @@ void RemoteFontFaceSource::beginLoadIfNeeded() {
     m_histograms.loadStarted();
   }
 
+  if (m_display == FontDisplaySwap && m_font->isLoading() &&
+      !m_font->loader()->isCacheAwareLoadingActivated()) {
+    // |m_period| might be modified if font load timeout callbacks are called
+    // during |m_font->addClient()| in constructor. Currently this should not
+    // happen with |m_display == FontDisplaySwap|.

[Shao-Chuan Lee, 2016/11/01 08:57:07]

ksakamoto@: I guess the if statement explains itself and this comment should be
sufficient?

+    DCHECK_EQ(m_period, BlockPeriod);
+    m_period = SwapPeriod;
+  }
+
   if (m_face)
     m_face->didBeginLoad();
 }