[DevTools] Implement screen orientation override.

LayoutTests/http/tests/inspector/inspector-test.js

 var initialize_InspectorTest = function() {
 
 var results = [];
 
 function consoleOutputHook(messageType)
 {
     InspectorTest.addResult(messageType + ": " + Array.prototype.slice.call(arguments, 1));
 }
 
 window._originalConsoleLog = console.log.bind(console);
@@ skipping 798 matching lines @@
         InspectorTest.DOMDebuggerAgent = target.domdebuggerAgent();
         InspectorTest.DebuggerAgent = target.debuggerAgent();
         InspectorTest.EmulationAgent = target.emulationAgent();
         InspectorTest.HeapProfilerAgent = target.heapProfilerAgent();
         InspectorTest.InspectorAgent = target.inspectorAgent();
         InspectorTest.LayerTreeAgent = target.layerTreeAgent();
         InspectorTest.NetworkAgent = target.networkAgent();
         InspectorTest.PageAgent = target.pageAgent();
         InspectorTest.ProfilerAgent = target.profilerAgent();
         InspectorTest.RuntimeAgent = target.runtimeAgent();
+        InspectorTest.ScreenOrientationAgent = target.screenOrientationAgent();
         InspectorTest.WorkerAgent = target.workerAgent();
 
         InspectorTest.consoleModel = target.consoleModel;
         InspectorTest.networkManager = target.networkManager;
         InspectorTest.resourceTreeModel = target.resourceTreeModel;
         InspectorTest.networkLog = target.networkLog;
         InspectorTest.debuggerModel = WebInspector.DebuggerModel.fromTarget(target);
         InspectorTest.runtimeModel = target.runtimeModel;
         InspectorTest.domModel = WebInspector.DOMModel.fromTarget(target);
         InspectorTest.cssModel = WebInspector.CSSStyleModel.fromTarget(target);
@@ skipping 232 matching lines @@
     _output("[page] " + text);
 }
 
 function _output(result)
 {
     if (!outputElement)
         createOutputElement();
     outputElement.appendChild(document.createTextNode(result));
     outputElement.appendChild(document.createElement("br"));
 }