Use removeFontFace to avoid resetting fontSelector.

Source/core/css/FontFaceCache.cpp

Index: Source/core/css/FontFaceCache.cpp
diff --git a/Source/core/css/FontFaceCache.cpp b/Source/core/css/FontFaceCache.cpp
index 91064ea425ced40d190f02dbcaba08f08074335b..1e8a530e2e9bc23336122a65acff32ac0274c79d 100644
--- a/Source/core/css/FontFaceCache.cpp
+++ b/Source/core/css/FontFaceCache.cpp
@@ -107,6 +107,13 @@ void FontFaceCache::removeFontFace(FontFace* fontFace, bool cssConnected)
     ++m_version;
 }
 
+void FontFaceCache::clear()
+{
+    for (StyleRuleToFontFace::iterator it = m_styleRuleToFontFace.begin(); it != m_styleRuleToFontFace.end(); ++it)
+        removeFontFace(it->value.get(), true);

[eseidel, 2014/02/14 05:39:15]

bools as arguments are horrible.  Obviously not your fault here, but something
we should eventually clean up

[tasak, 2014/02/14 08:27:46]

I see. I will discuss with ksakamoto@. I think, he is an expert in WebFont /
FontSelector.

+    m_styleRuleToFontFace.clear();
+}
+
 static inline bool compareFontFaces(CSSSegmentedFontFace* first, CSSSegmentedFontFace* second, FontTraitsMask desiredTraitsMask)
 {
     FontTraitsMask firstTraitsMask = first->traitsMask();