Merge pull request #4182 from deepak1556/debugger_api_patch

browser: add webContents.debugger api

docs/api/web-contents.md

@@ -833,3 +833,73 @@ Get the `WebContents` of DevTools for this `WebContents`.
 
 **Note:** Users should never store this object because it may become `null`
 when the DevTools has been closed.
+
+### `webContents.debugger`
+
+Debugger API serves as an alternate transport for [remote debugging protocol][rdp].
+
+```javascript
+try {
+  win.webContents.debugger.attach("1.1");
+} catch(err) {
+  console.log("Debugger attach failed : ", err);
+};
+
+win.webContents.debugger.on('detach', function(event, reason) {
+  console.log("Debugger detached due to : ", reason);
+});
+
+win.webContents.debugger.on('message', function(event, method, params) {
+  if (method == "Network.requestWillBeSent") {
+    if (params.request.url == "https://www.github.com")
+      win.webContents.debugger.detach();
+  }
+})
+
+win.webContents.debugger.sendCommand("Network.enable");
+```
+
+#### `webContents.debugger.attach([protocolVersion])`
+
+* `protocolVersion` String (optional) - Requested debugging protocol version.
+
+Attaches the debugger to the `webContents`.
+
+#### `webContents.debugger.isAttached()`
+
+Returns a boolean indicating whether a debugger is attached to the `webContents`.
+
+#### `webContents.debugger.detach()`
+
+Detaches the debugger from the `webContents`.
+
+#### `webContents.debugger.sendCommand(method[, commandParams, callback])`
+
+* `method` String - Method name, should be one of the methods defined by the
+   remote debugging protocol.
+* `commandParams` Object (optional) - JSON object with request parameters.
+* `callback` Function (optional) - Response
+  * `error` Object - Error message indicating the failure of the command.
+  * `result` Object - Response defined by the 'returns' attribute of
+     the command description in the remote debugging protocol.
+
+Send given command to the debugging target.
+
+#### Event: 'detach'
+
+* `event` Event
+* `reason` String - Reason for detaching debugger.
+
+Emitted when debugging session is terminated. This happens either when
+`webContents` is closed or devtools is invoked for the attached `webContents`.
+
+#### Event: 'message'
+
+* `event` Event
+* `method` String - Method name.
+* `params` Object - Event parameters defined by the 'parameters'
+   attribute in the remote debugging protocol.
+
+Emitted whenever debugging target issues instrumentation event.
+
+[rdp]: https://developer.chrome.com/devtools/docs/debugger-protocol