Avoid re-parsing of string in fillText and measureText in Canvas

Source/platform/fonts/Font.cpp

Index: Source/platform/fonts/Font.cpp
diff --git a/Source/platform/fonts/Font.cpp b/Source/platform/fonts/Font.cpp
index 6131fb8db99034c5646e5442e974072b97daeee9..9cfc4d3b057cf9a9dfc25672668dc125984a37fd 100644
--- a/Source/platform/fonts/Font.cpp
+++ b/Source/platform/fonts/Font.cpp
@@ -391,7 +391,7 @@ static inline std::pair<GlyphData, GlyphPage*> glyphDataAndPageForNonCJKCharacte
     return std::make_pair(data, page);
 }
 
-std::pair<GlyphData, GlyphPage*> Font::glyphDataAndPageForCharacter(UChar32 c, bool mirror, FontDataVariant variant) const
+std::pair<GlyphData, GlyphPage*> Font::glyphDataAndPageForCharacter(UChar32& c, bool mirror, bool spaceNormalize, FontDataVariant variant) const
 {
     ASSERT(isMainThread());
 
@@ -409,6 +409,9 @@ std::pair<GlyphData, GlyphPage*> Font::glyphDataAndPageForCharacter(UChar32 c, b
         }
     }
 
+    if (spaceNormalize && Character::isNormalizedCanvasSpaceCharacter(c))
+        c = space;
+
     if (mirror)
         c = mirroredChar(c);
 
@@ -566,7 +569,7 @@ bool Font::getEmphasisMarkGlyphData(const AtomicString& mark, GlyphData& glyphDa
         character = U16_GET_SUPPLEMENTARY(character, low);
     }
 
-    glyphData = glyphDataForCharacter(character, false, EmphasisMarkVariant);
+    glyphData = glyphDataForCharacter(character, false, false, EmphasisMarkVariant);

[eae, 2014/09/16 00:46:33]

bool normalizeSpace = false;

glyphData = glyphDataForCharacter(character, false, normalizeSpace,
EmphasisMarkVariant);

[h.joshi, 2014/09/16 05:48:11]

Done.

     return true;
 }