Change image document zooming logic.

third_party/WebKit/Source/core/testing/DummyPageHolder.cpp

Index: third_party/WebKit/Source/core/testing/DummyPageHolder.cpp
diff --git a/third_party/WebKit/Source/core/testing/DummyPageHolder.cpp b/third_party/WebKit/Source/core/testing/DummyPageHolder.cpp
index a95add4e1e6b8e83d499dd3b55c647bd3e6bec78..331874fc9df52ce15b9a17676aa0f39465113ceb 100644
--- a/third_party/WebKit/Source/core/testing/DummyPageHolder.cpp
+++ b/third_party/WebKit/Source/core/testing/DummyPageHolder.cpp
@@ -83,7 +83,7 @@ DummyPageHolder::DummyPageHolder(
     if (!m_frameLoaderClient)
         m_frameLoaderClient = EmptyFrameLoaderClient::create();
 
-    m_frame = LocalFrame::create(m_frameLoaderClient.get(), &m_page->frameHost(), 0);
+    m_frame = LocalFrame::create(m_frameLoaderClient.get(), &m_page->frameHost(), nullptr);
     m_frame->setView(FrameView::create(m_frame.get(), initialViewSize));
     m_frame->view()->page()->frameHost().visualViewport().setSize(initialViewSize);
     m_frame->init();