Use an array of values instead of object literals to save space in fontMetricsData.js

Test Plan: make test

Reviewers: emily

metrics/format_json.py

@@ -6,11 +6,17 @@ import json
 data = json.load(sys.stdin)
 sep = "module.exports = {\n"
 for font in sorted(data):
-  sys.stdout.write(sep + json.dumps(font))
-  sep = ": {\n  "
-  for glyph in sorted(data[font], key=int):
-      sys.stdout.write(sep + json.dumps(glyph) + ": ")
-      sys.stdout.write(json.dumps(data[font][glyph], sort_keys=True))
-      sep = ",\n  "
-  sep = "\n},\n"
-sys.stdout.write("\n}};\n");
+    sys.stdout.write(sep + json.dumps(font))
+    sep = ": {\n  "
+    for glyph in sorted(data[font], key=int):
+        sys.stdout.write(sep + json.dumps(glyph) + ": ")
+        
+        values = [data[font][glyph][key] for key in
+            ['depth', 'height', 'italic', 'skew']]
+            
+        values = [value if value != 0.0 else 0 for value in values]
+            
+        sys.stdout.write(json.dumps(values))
+        sep = ",\n  "
+    sep = "\n},\n"
+sys.stdout.write("\n}};\n")

src/fontMetrics.js

@@ -122,11 +122,19 @@ var metrics = {
 var metricMap = require("./fontMetricsData");
 
 /**
- * This function is a convience function for looking up information in the
+ * This function is a convenience function for looking up information in the
  * metricMap table. It takes a character as a string, and a style
  */
 var getCharacterMetrics = function(character, style) {
-    return metricMap[style][character.charCodeAt(0)];
+    var metrics = metricMap[style][character.charCodeAt(0)];
+    if (metrics) {
+        return {
+            depth: metrics[0],
+            height: metrics[1],
+            italic: metrics[2],
+            skew: metrics[3]
+        };
+    }
 };
 
 module.exports = {