bump SkStrAppendScalar_MaxSize to 15 to handle 3-digit exponents on some
platforms (like windows)



git-svn-id: http://skia.googlecode.com/svn/trunk@881 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkString.h b/include/core/SkString.h
index ba9de02..eb25e15 100644
--- a/include/core/SkString.h
+++ b/include/core/SkString.h
@@ -33,9 +33,12 @@
 
 /**
  *  Floats have at most 8 significant digits, so we limit our %g to that.
- *  However, the total string could be 14 characters: -1.2345678e+38
+ *  However, the total string could be 15 characters: -1.2345678e-005
+ *
+ *  In theory we should only expect up to 2 digits for the exponent, but on
+ *  some platforms we have seen 3 (as in the example above).
  */
-#define SkStrAppendScalar_MaxSize  14
+#define SkStrAppendScalar_MaxSize  15
 
 /**
  *  Write the scaler in decimal format into buffer, and return a pointer to