[DevTools] Fixed multiline error messages

Source/core/inspector/InjectedScriptSource.js

Index: Source/core/inspector/InjectedScriptSource.js
diff --git a/Source/core/inspector/InjectedScriptSource.js b/Source/core/inspector/InjectedScriptSource.js
index 2dd90d51ef58a36651fc9e4e59a70448b46c1914..46b940105a827bb3452a9627e01fd9f0c03d1701 100644
--- a/Source/core/inspector/InjectedScriptSource.js
+++ b/Source/core/inspector/InjectedScriptSource.js
@@ -1212,9 +1212,10 @@ InjectedScript.prototype = {
             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;