title - smarter devtools handling with custom title

src/vs/code/electron-main/menus.ts

@@ -660,7 +660,12 @@ export class VSCodeMenu {
 	private toggleDevTools(): void {
 		const w = this.windowsService.getFocusedWindow();
 		if (w && w.win) {
-			w.win.webContents.toggleDevTools();
+			const contents = w.win.webContents;
+			if (w.hasHiddenTitleBarStyle() && !w.win.isFullScreen() && !contents.isDevToolsOpened()) {
+				contents.openDevTools({ mode: 'undocked' }); // due to https://github.com/electron/electron/issues/3647
+			} else {
+				contents.toggleDevTools();
+			}
 		}
 	}
 

src/vs/code/electron-main/window.ts

@@ -227,6 +227,10 @@ export class VSCodeWindow {
 		this.registerListeners();
 	}
 
+	public hasHiddenTitleBarStyle(): boolean {
+		return this.options && this.options.titleBarStyle === 'custom';
+	}
+
 	public get isPluginDevelopmentHost(): boolean {
 		return !!this._extensionDevelopmentPath;
 	}

src/vs/platform/windows/electron-main/windowsService.ts

@@ -61,7 +61,12 @@ export class WindowsService implements IWindowsService {
 		const vscodeWindow = this.windowsMainService.getWindowById(windowId);
 
 		if (vscodeWindow) {
-			vscodeWindow.win.webContents.toggleDevTools();
+			const contents = vscodeWindow.win.webContents;
+			if (vscodeWindow.hasHiddenTitleBarStyle() && !vscodeWindow.win.isFullScreen() && !contents.isDevToolsOpened()) {
+				contents.openDevTools({ mode: 'undocked' }); // due to https://github.com/electron/electron/issues/3647
+			} else {
+				contents.toggleDevTools();
+			}
 		}
 
 		return TPromise.as(null);