[DevTools] Blink-side APIs for device metrics emulation in content.

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 97a2357b74e8a865e02a2ad8f9d77c9d03a4c906..ca0ddc7bb21b392181f2a278f4c66bfd01f8fc8b 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -3481,6 +3481,14 @@ void WebViewImpl::setInspectorSetting(const WebString& key,
     client()->didUpdateInspectorSetting(key, value);
 }
 
+void WebViewImpl::setCompositorDeviceScaleFactorOverride(float deviceScaleFactor)
+{
+}
+
+void WebViewImpl::setRootLayerScaleTransform(float rootLayerScale)
+{
+}
+
 WebDevToolsAgent* WebViewImpl::devToolsAgent()
 {
     return m_devToolsAgent.get();