DevTools: Extenstions: use request.contentEncoded for GetRequestContent

Source/devtools/front_end/extensions/ExtensionServer.js

Index: Source/devtools/front_end/extensions/ExtensionServer.js
diff --git a/Source/devtools/front_end/extensions/ExtensionServer.js b/Source/devtools/front_end/extensions/ExtensionServer.js
index 7a19e432aa0ded4d19e5395ef9a0264f4049d694..af3e6befa7d9c2dfff873cc8ac405f1753d9c436 100644
--- a/Source/devtools/front_end/extensions/ExtensionServer.js
+++ b/Source/devtools/front_end/extensions/ExtensionServer.js
@@ -560,8 +560,13 @@ WebInspector.ExtensionServer.prototype = {
          */
         function onContentAvailable(content)
         {
+            var contentEncoded = false;
+            if (contentProvider instanceof WebInspector.Resource)
+                contentEncoded = contentProvider.contentEncoded;
+            if (contentProvider instanceof WebInspector.NetworkRequest)
+                contentEncoded = contentProvider.contentEncoded;
             var response = {
-                encoding: (content === null) || contentProvider.contentType().isTextType() ? "" : "base64",
+                encoding: contentEncoded && content ? "base64" : "",
                 content: content
             };
             this._dispatchCallback(message.requestId, port, response);