Modifying crazyfun Closure compilation to read command-line flags fro…

…m file

Because of the large number of JavaScript files we pass through the
Closure compiler for some targets, we are running over the 8192 character
limit of the command line in Windows. The workaround is to have the
Closure compiler read its command-line flags from a file instead.

rake-tasks/crazy_fun/mappings/javascript.rb

@@ -557,20 +557,25 @@ def handle(fun, dir, args)
 
         flags.push("--js_output_file=#{output}")
 
-        cmd = "java -cp third_party/closure/bin/compiler.jar com.google.javascript.jscomp.CommandLineRunner " <<
-           flags.join(" ") <<
+        expanded_flags = flags.join(" ") <<
            " --js='" <<
            all_deps.join("' --js='") << "'"
 
         if (args[:externs])
           args[:externs].each do |extern|
-            cmd << " --externs=#{File.join(dir, extern)} "
+            expanded_flags << " --externs=#{File.join(dir, extern)} "
           end
         end
 
         mkdir_p File.dirname(output)
 
+        flag_file = File.join(File.dirname(output), "closure_flags.txt")
+        File.open(flag_file, 'w') {|f| f.write(expanded_flags)}    
+
+        cmd = "java -cp third_party/closure/bin/compiler.jar com.google.javascript.jscomp.CommandLineRunner --flagfile " << flag_file
         sh cmd
+
+        rm_rf flag_file
       end
     end
   end