Added MockPresentationClient to use in layout tests.

content/shell/renderer/test_runner/web_test_proxy.cc

Index: content/shell/renderer/test_runner/web_test_proxy.cc
diff --git a/content/shell/renderer/test_runner/web_test_proxy.cc b/content/shell/renderer/test_runner/web_test_proxy.cc
index da62fc05f003e2c24df25866a0e3c31f7676eddf..62ad083120e5379e58e63c2c7fc71241c5eabb61 100644
--- a/content/shell/renderer/test_runner/web_test_proxy.cc
+++ b/content/shell/renderer/test_runner/web_test_proxy.cc
@@ -18,6 +18,7 @@
 #include "content/shell/renderer/test_runner/event_sender.h"
 #include "content/shell/renderer/test_runner/mock_color_chooser.h"
 #include "content/shell/renderer/test_runner/mock_credential_manager_client.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/mock_web_speech_recognizer.h"
 #include "content/shell/renderer/test_runner/mock_web_user_media_client.h"
@@ -652,6 +653,12 @@ WebTestProxyBase::GetCredentialManagerClientMock() {
   return credential_manager_client_.get();
 }
 
+MockPresentationClient* WebTestProxyBase::GetPresentationClientMock() {
+  if (!presentation_client_.get())
+    presentation_client_.reset(new MockPresentationClient());
+  return presentation_client_.get();
+}
+
 void WebTestProxyBase::ScheduleAnimation() {
   if (!test_interfaces_->GetTestRunner()->TestIsRunning())
     return;