Use process/control messages (instead of RVH messages) for layout tests.

third_party/WebKit/LayoutTests/inspector-protocol/runtime/runtime-console-line-and-column-expected.txt

 CONSOLE MESSAGE: line 1: 239
+CONSOLE ERROR: line 1: Uncaught TypeError: DevToolsAPI.embedderMessageAck is not a function
+CONSOLE ERROR: line 1: Uncaught TypeError: DevToolsAPI.embedderMessageAck is not a function
+CONSOLE ERROR: line 1: Uncaught TypeError: DevToolsAPI.embedderMessageAck is not a function
+CONSOLE ERROR: line 1: Uncaught TypeError: DevToolsAPI.embedderMessageAck is not a function
 CONSOLE MESSAGE: line 2: 239
+CONSOLE ERROR: line 1: Uncaught TypeError: DevToolsAPI.embedderMessageAck is not a function
+CONSOLE ERROR: line 1: Uncaught TypeError: DevToolsAPI.embedderMessageAck is not a function
 {
     stackTrace : {
         callFrames : [
             [0] : {
                 columnNumber : 8
                 functionName : 
                 lineNumber : 0
                 scriptId : 0
                 url : 
             }
         ]
     }
     type : log
 }
 {
     stackTrace : {
         callFrames : [
             [0] : {
                 columnNumber : 2
                 functionName : 
                 lineNumber : 1
                 scriptId : 0
                 url : 
             }
         ]
     }
     type : log
 }