DevTools: [CSS] promisify CSS domain

LayoutTests/inspector/inspector-backend-commands-expected.txt

Index: LayoutTests/inspector/inspector-backend-commands-expected.txt
diff --git a/LayoutTests/inspector/inspector-backend-commands-expected.txt b/LayoutTests/inspector/inspector-backend-commands-expected.txt
index 2147740a58331c0967206c802bd1d8c37857f4e3..d11ea6cc6de29e608058ecd2d94b62ff1360bf37 100644
--- a/LayoutTests/inspector/inspector-backend-commands-expected.txt
+++ b/LayoutTests/inspector/inspector-backend-commands-expected.txt
@@ -1,26 +1,25 @@
 Tests correctness of promisified protocol commands.
 
 error: Request with id = ## failed. {"message":"this is the error message"}
-error: this is the error message
-commandError: then result: null
-commandArgs0: then result: undefined
+commandError: then result: ["this is the error message"]
+commandArgs0: then result: [null]
 error: Protocol Error: Optional callback argument for method 'Profiler.commandArgs0' call must be a function but its type is 'number'.
 commandArgs0: catch result: {}
-commandArgs1Rets0: then result: undefined
+commandArgs1Rets0: then result: [null]
 error: Protocol Error: Optional callback argument for method 'Profiler.commandArgs1Rets0' call must be a function but its type is 'number'.
 commandArgs1Rets0: catch result: {}
 error: Protocol Error: Invalid type of argument 'arg1' for method 'Profiler.commandArgs1Rets0' call. It must be 'number' but it is 'string'.
 commandArgs1Rets0: catch result: {}
 error: Protocol Error: Invalid number of arguments for method 'Profiler.commandArgs1Rets0' call. It must have the following arguments '[{"name":"arg1","type":"number","optional":false}]'.
 commandArgs1Rets0: catch result: {}
-commandArgs1Rets1: then result: {"arg1":{"value1":234}}
-commandArgs1Rets1: then result: {"arg1":{"value1":234}}
-commandArgs3Rets3: then result: {"arg1":{},"arg2":345,"arg3":"alph"}
-commandArgs3Rets3: then result: {"arg1":{},"arg2":345}
-commandArgs3Rets3: then result: {"arg1":{},"arg3":"alph"}
+commandArgs1Rets1: then result: [null,{"value1":234}]
+commandArgs1Rets1: then result: [null,{"value1":234}]
+commandArgs3Rets3: then result: [null,{},345,"alph"]
+commandArgs3Rets3: then result: [null,{},345,null]
+commandArgs3Rets3: then result: [null,{},null,"alph"]
 error: Protocol Error: Invalid type of argument 'arg2' for method 'Profiler.commandArgs3Rets3' call. It must be 'number' but it is 'string'.
 commandArgs3Rets3: catch result: {}
-commandArgs3Rets3: then result: {"arg1":{}}
+commandArgs3Rets3: then result: [null,{},null,null]
 error: Protocol Error: Invalid number of arguments for method 'Profiler.commandArgs3Rets3' call. It must have the following arguments '[{"name":"arg1","type":"object","optional":false},{"name":"arg2","type":"number","optional":true},{"name":"arg3","type":"string","optional":true}]'.
 commandArgs3Rets3: catch result: {}
 error: Protocol Error: Invalid type of argument 'arg2' for method 'Profiler.commandArgs3Rets3' call. It must be 'number' but it is 'string'.