Make font-size-adjust animatable.

Source/core/css/resolver/FontBuilder.cpp

Index: Source/core/css/resolver/FontBuilder.cpp
diff --git a/Source/core/css/resolver/FontBuilder.cpp b/Source/core/css/resolver/FontBuilder.cpp
index f4ac93595588604e94b3f5118cb37d9e43b2199b..470231a2291f6e086869c008ee3ca274ed2eb877 100644
--- a/Source/core/css/resolver/FontBuilder.cpp
+++ b/Source/core/css/resolver/FontBuilder.cpp
@@ -335,6 +335,11 @@ void FontBuilder::updateAdjustedSize(FontDescription& fontDescription, const Lay
         return;
 
     // We need to create a temporal Font to get xHeight of a primary font.
+    // To get an accurate x-height from a font cache while animation, we need to reset adjustedSize

[rune, 2015/03/06 10:08:06]

... while animating ...

[changseok, 2015/03/08 06:16:56]

Done.

+    // before creating a Font. Because a retrived font data from the cache is based on a FontCacheKey
+    // and which is affected by effectiveFontSize.

[rune, 2015/03/06 10:08:05]

-and

[changseok, 2015/03/08 06:16:56]

Done.

+    fontDescription.setAdjustedSize(0);

[rune, 2015/03/06 10:08:06]

This is necessary in general to get the correct result when calling
updateFont(), hence createFont(), multiple times on the same FontBuilder. This
happens to be the case for animations only at the moment, but the comment should
probably say something along the lines of:

"The aspect value is based on the x-height of the font for the computed font
size, so we need to reset the adjustment."

Would that be correct?

[changseok, 2015/03/08 06:16:56]

Yes correct. thanks for the summary =)

+
     Font font(fontDescription);
     font.update(fontSelector);
     if (!font.fontMetrics().hasXHeight())