Added MockPresentationClient to use in layout tests.

content/shell/renderer/test_runner/test_runner.cc

Index: content/shell/renderer/test_runner/test_runner.cc
diff --git a/content/shell/renderer/test_runner/test_runner.cc b/content/shell/renderer/test_runner/test_runner.cc
index 7bf164bbfbb5dbf71db4a03aa041a4f82b4e3cc7..cd91523abfa0b998b9032183a02af5377e943390 100644
--- a/content/shell/renderer/test_runner/test_runner.cc
+++ b/content/shell/renderer/test_runner/test_runner.cc
@@ -204,6 +204,7 @@ class TestRunnerBindings : public gin::Wrappable<TestRunnerBindings> {
                               double dischargingTime,
                               double level);
   void ResetBatteryStatus();
+  void SetMockScreenAvailability(bool available);
   void DidAcquirePointerLock();
   void DidNotAcquirePointerLock();
   void DidLosePointerLock();
@@ -410,6 +411,8 @@ gin::ObjectTemplateBuilder TestRunnerBindings::GetObjectTemplateBuilder(
       .SetMethod("didChangeBatteryStatus",
                  &TestRunnerBindings::DidChangeBatteryStatus)
       .SetMethod("resetBatteryStatus", &TestRunnerBindings::ResetBatteryStatus)
+      .SetMethod("setMockScreenAvailability",
+                 &TestRunnerBindings::SetMockScreenAvailability)
       .SetMethod("didAcquirePointerLock",
                  &TestRunnerBindings::DidAcquirePointerLock)
       .SetMethod("didNotAcquirePointerLock",
@@ -964,6 +967,11 @@ void TestRunnerBindings::ResetBatteryStatus() {
     runner_->ResetBatteryStatus();
 }
 
+void TestRunnerBindings::SetMockScreenAvailability(bool available) {
+  if (runner_)
+    runner_->SetMockScreenAvailability(available);
+}
+
 void TestRunnerBindings::DidAcquirePointerLock() {
   if (runner_)
     runner_->DidAcquirePointerLock();
@@ -2447,6 +2455,10 @@ void TestRunner::ResetBatteryStatus() {
   delegate_->DidChangeBatteryStatus(status);
 }
 
+void TestRunner::SetMockScreenAvailability(bool available) {
+  delegate_->SetScreenAvailability(available);
+}
+
 void TestRunner::DidAcquirePointerLock() {
   DidAcquirePointerLockInternal();
 }