[chrome.dial] Adds chrome.dial.fetchDeviceDecription API.

chrome/browser/extensions/api/dial/dial_device_data.h

Index: chrome/browser/extensions/api/dial/dial_device_data.h
diff --git a/chrome/browser/extensions/api/dial/dial_device_data.h b/chrome/browser/extensions/api/dial/dial_device_data.h
index 87eacffc036efc893cf8210bbf3f0a6946f7de9d..4706885a465399094231af55d21504714f6dec06 100644
--- a/chrome/browser/extensions/api/dial/dial_device_data.h
+++ b/chrome/browser/extensions/api/dial/dial_device_data.h
@@ -92,6 +92,16 @@ class DialDeviceData {
   int config_id_;
 };
 
+struct DialDeviceDescriptionData {
+ public:
+  DialDeviceDescriptionData() = default;
+  DialDeviceDescriptionData(const std::string& device_description,
+                            const GURL& app_url);
+
+  std::string device_description;
+  GURL app_url;
+};
+
 }  // namespace dial
 }  // namespace api
 }  // namespace extensions