Added MockPresentationClient to use in layout tests.

content/shell/renderer/layout_test/webkit_test_runner.cc

Index: content/shell/renderer/layout_test/webkit_test_runner.cc
diff --git a/content/shell/renderer/layout_test/webkit_test_runner.cc b/content/shell/renderer/layout_test/webkit_test_runner.cc
index 28c12fc0187a606c79209134d9b25d68d9442a47..8b05d4c2c044d462e028a78af3284a8de571496b 100644
--- a/content/shell/renderer/layout_test/webkit_test_runner.cc
+++ b/content/shell/renderer/layout_test/webkit_test_runner.cc
@@ -35,6 +35,7 @@
 #include "content/shell/renderer/layout_test/gc_controller.h"
 #include "content/shell/renderer/layout_test/layout_test_render_process_observer.h"
 #include "content/shell/renderer/layout_test/leak_detector.h"
+#include "content/shell/renderer/test_runner/mock_presentation_client.h"
 #include "content/shell/renderer/test_runner/mock_screen_orientation_client.h"
 #include "content/shell/renderer/test_runner/web_task.h"
 #include "content/shell/renderer/test_runner/web_test_interfaces.h"
@@ -248,6 +249,11 @@ void WebKitTestRunner::DidChangeBatteryStatus(
   MockBatteryStatusChanged(status);
 }
 
+void WebKitTestRunner::SetScreenAvailability(bool available) {
+  MockPresentationClient* mock_client = proxy()->GetPresentationClientMock();
+  mock_client->SetScreenAvailability(available);
+}
+
 void WebKitTestRunner::PrintMessage(const std::string& message) {
   Send(new ShellViewHostMsg_PrintMessage(routing_id(), message));
 }