Convert more this.exports to module.exports

TBR=esprehn@chromium.org

Review URL: https://codereview.chromium.org/685323003

framework/inspector/css-agent.sky

@@ -47,5 +47,5 @@ CSS.prototype.getComputedStyleForNode = function(params) {
   }
 }
 
-this.exports = CSS;
+module.exports = CSS;
 </script>

framework/inspector/debug.sky

@@ -9,7 +9,7 @@ function loggingStub(name) {
   }
 }
 
-this.exports = {
+module.exports = {
     logParams: logParams,
     loggingStub: loggingStub,
 }