[DevTools] Add awaitPromise flag to Runtime.runScript

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

 CONSOLE ERROR: Uncaught (in promise) 239
 Tests that Runtime.evaluate works with awaitPromise flag.
 
 Running test: testResolvedPromise
 {
     result : {
         description : 239
         type : number
         value : 239
     }
@@ skipping 15 matching lines @@
         description : 239
         type : number
         value : 239
     }
     wasThrown : true
 }
 
 Running test: testPrimitiveValueInsteadOfPromise
 {
     code : -32000
-    message : Result of expression is not a promise.
+    message : Result of the evaluation is not a promise
 }
 
 Running test: testObjectInsteadOfPromise
 {
     code : -32000
-    message : Result of expression is not a promise.
+    message : Result of the evaluation is not a promise
 }
 
 Running test: testPendingPromise
 {
     result : {
         type : object
         value : {
             a : 239
         }
     }
 }
 
 Running test: testExceptionInEvaluate
 {
     exceptionDetails : {
         columnNumber : 0
         lineNumber : 0
         scriptId : 
         text : Uncaught 239
     }
     result : {
         description : 239
         type : number
         value : 239
     }
     wasThrown : true
 }