[DevTools] Add awaitPromise flag to Runtime.runScript

third_party/WebKit/LayoutTests/inspector-protocol/runtime/runtime-callFunctionOn-async-expected.txt

 CONSOLE ERROR: Uncaught (in promise) #<Object>
 Tests that Runtime.callFunctionOn works with awaitPromise flag.
 
 Running test: testArguments
 {
     result : {
         type : string
         value : undefined|NaN|[object Object]|[object Window]
     }
     wasThrown : false
@@ skipping 31 matching lines @@
         objectId : [ObjectId]
         subtype : error
         type : object
     }
     wasThrown : true
 }
 
 Running test: testFunctionReturnNotPromise
 {
     code : -32000
-    message : Result of the function call is not a promise.
+    message : Result of the function call is not a promise
 }
 
 Running test: testFunctionReturnResolvedPromiseReturnByValue
 {
     result : {
         type : object
         value : {
             a : 3
         }
     }
@@ skipping 35 matching lines @@
     }
     result : {
         type : object
         value : {
             a : 3
         }
     }
     wasThrown : true
 }