Add beginnings of an inspector backend for Sky

sky/framework/inspector/page-agent.sky

Index: sky/framework/inspector/page-agent.sky
diff --git a/sky/framework/inspector/page-agent.sky b/sky/framework/inspector/page-agent.sky
new file mode 100644
index 0000000000000000000000000000000000000000..053954caaf281662a06c42bfb75fbfdec3b1972d
--- /dev/null
+++ b/sky/framework/inspector/page-agent.sky
@@ -0,0 +1,21 @@
+<script>
+function PageAgent() {
+}
+
+PageAgent.prototype.enable = function() {
+};
+
+PageAgent.prototype.canScreencast = function() {
+  return {
+    result: false
+  };
+};
+
+PageAgent.prototype.canEmulate = function() {
+  return {
+    result: false
+  };
+};
+
+this.exports = PageAgent;
+</script>