Tests WebInspector extension API

Started extension.
Running tests...
RUNNING TEST: extension_testEvalInContentScriptContext
Evaluate: "brave new world" (exception: undefined)
RUNNING TEST: extension_testEvalInMainWorldExplicit
Evaluate: "main world" (exception: undefined)
RUNNING TEST: extension_testEvalInMainWorldImplicit
Evaluate: "main world" (exception: undefined)
All tests done.