Initial implementation of font-size-adjust

Source/platform/fonts/FontDescription.cpp

Index: Source/platform/fonts/FontDescription.cpp
diff --git a/Source/platform/fonts/FontDescription.cpp b/Source/platform/fonts/FontDescription.cpp
index 85d0035d9ede83e326602953a3484be49e24ed30..6111fe63bf6a98db015eba9f39de5dfb9d945de7 100644
--- a/Source/platform/fonts/FontDescription.cpp
+++ b/Source/platform/fonts/FontDescription.cpp
@@ -40,7 +40,7 @@ struct SameSizeAsFontDescription {
     FontFamily familyList;
     RefPtr<FontFeatureSettings> m_featureSettings;
     AtomicString locale;
-    float sizes[4];
+    float sizes[5];
     // FXIME: Make them fit into one word.
     uint32_t bitfields;
     uint32_t bitfields2 : 7;
@@ -160,7 +160,8 @@ float FontDescription::effectiveFontSize() const
 {
     // Ensure that the effective precision matches the font-cache precision.
     // This guarantees that the same precision is used regardless of cache status.
-    return floorf(computedSize() * FontCacheKey::precisionMultiplier()) / FontCacheKey::precisionMultiplier();
+    float computedOrAdjustedSize = adjustedSize() ? adjustedSize() : computedSize();
+    return floorf(computedOrAdjustedSize * FontCacheKey::precisionMultiplier()) / FontCacheKey::precisionMultiplier();
 }
 
 FontCacheKey FontDescription::cacheKey(const FontFaceCreationParams& creationParams, FontTraits desiredTraits) const