DevTools: cleanup debugger tests.

LayoutTests/inspector/sources/debugger/properties-special-expected.txt

 Tests how debugger presents special properties of closures, bound functions and object wrappers.
 
-Debugger was enabled.
 Script source was shown.
 Set timer for test function.
 Watch expressions updated.
 Nodes are expanded.
 'Object(true)' => 'Boolean'
     '__proto__' => 'Boolean'
     '[[PrimitiveValue]]' => 'true'
 '(function(a,b) { return a + b; })' => 'function (a,b) { return a + b; }'
     'arguments' => 'null'
     'caller' => 'null'
     'length' => '2'
     'name' => '""'
     'prototype' => 'Object'
     '__proto__' => 'function Empty() {}'
     <function scope>
 '(function(a,b) { return a + b; }).bind({}, 2)' => 'function () { [native code] }'
     'arguments' => '(...)'
     'get arguments' => 'function ThrowTypeError() { [native code] }'
     'set arguments' => 'function ThrowTypeError() { [native code] }'
     'caller' => '(...)'
     'get caller' => 'function ThrowTypeError() { [native code] }'
     'set caller' => 'function ThrowTypeError() { [native code] }'
     'length' => '1'
     'name' => '""'
     '__proto__' => 'function Empty() {}'
     '[[TargetFunction]]' => 'function (a,b) { return a + b; }'
     '[[BoundThis]]' => 'Object'
     '[[BoundArgs]]' => 'Array[1]'
-Debugger was disabled.