[DevTools] Fixed multiline error messages

Source/core/inspector/InjectedScriptSource.js

 /*
  * Copyright (C) 2007 Apple Inc.  All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 1194 matching lines @@
                 return /** @type {string} */ (InjectedScriptHost.callFunction(Symbol.prototype.toString, obj)) || "Symbol";
             } catch (e) {
                 return "Symbol";
             }
         }
 
         if (InjectedScriptHost.subtype(obj) === "error") {
             try {
                 var stack = obj.stack;
                 var message = obj.message && obj.message.length ? ": " + obj.message : "";
-                var stackMessageEnd = stack ? indexOf(stack, "\n") : -1;
+                var firstCallFrame = /^\s*at\s/m.exec(stack);

[yurys, 2015/06/15 14:21:51]

I believe stack frames always start with " at ", i.e. one space before "at" and
ends with :\d+:\d\), can we provide more strict regex?
Also it might make sense to cache the regex.

[kozy, 2015/06/16 10:22:53]

Yes, it starts from spaces. This line is generated in [1]. Done.
End of string is generated in [2] and it isn't contain ending with :\d in all
cases.
In devtools source code we've already one regex for call frame in
ConsoleViewMessages.js [3]: var isCallFrameLine = /^\s*at\s/.test(lines[i]);

We use regex in InjectedScriptSource without caching for generating preview of
element nodes. I suppose that we can ignore it here too.

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/v8/src/messages.js...
[2]
https://code.google.com/p/chromium/codesearch#chromium/src/v8/src/messages.js...
[3]
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

+                var stackMessageEnd = firstCallFrame ? firstCallFrame.index : -1;
                 if (stackMessageEnd !== -1) {
-                    var stackTrace = stack.substr(stackMessageEnd + 1);
+                    var stackTrace = stack.substr(stackMessageEnd);
                     return className + message + "\n" + stackTrace;
                 }
                 return className + message;
             } catch(e) {
             }
         }
 
         return className;
     },
 
@@ skipping 798 matching lines @@
      */
     _logEvent: function(event)
     {
         inspectedGlobalObject.console.log(event.type, event);
     }
 }
 
 injectedScript._commandLineAPIImpl = new CommandLineAPIImpl();
 return injectedScript;
 })