cast channel error cleanup

extensions/browser/api/cast_channel/cast_channel_api.h

Index: extensions/browser/api/cast_channel/cast_channel_api.h
diff --git a/extensions/browser/api/cast_channel/cast_channel_api.h b/extensions/browser/api/cast_channel/cast_channel_api.h
index ebaf41867c7461caa50fc4d44f6b4d9916e30014..b8c0c4e8956f5920ea821dc5e4cb26b614bb6c1c 100644
--- a/extensions/browser/api/cast_channel/cast_channel_api.h
+++ b/extensions/browser/api/cast_channel/cast_channel_api.h
@@ -116,8 +116,14 @@ class CastChannelAsyncApiFunction : public AsyncApiFunction {
   void SetResultFromSocket(const cast_channel::CastSocket& socket);
 
   // Sets the function result to a ChannelInfo populated with |channel_id| and
-  // |error|.
-  void SetResultFromError(int channel_id, cast_channel::ChannelError error);
+  // |channel_error|.
+  void SetResultFromError(int channel_id,
+                          cast_channel::ChannelError channel_error);
+
+  // Sets extension lastError to |error| and function result to |channel_error|.
+  void SetChannelError(const std::string& error,
+                       cast_channel::ChannelError channel_error =
+                           cast_channel::CHANNEL_ERROR_UNKNOWN);
 
   // Returns the socket corresponding to |channel_id| if one exists, or null
   // otherwise.
@@ -131,7 +137,7 @@ class CastChannelAsyncApiFunction : public AsyncApiFunction {
   ApiResourceManager<cast_channel::CastSocket>* manager_;
 
   // The result of the function.
-  cast_channel::ChannelError error_;
+  cast_channel::ChannelError channel_error_;
 };
 
 class CastChannelOpenFunction : public CastChannelAsyncApiFunction {