Add tests and settings plumbing for accelerated fixed root background

Source/WebKit/chromium/src/WebSettingsImpl.cpp

Index: Source/WebKit/chromium/src/WebSettingsImpl.cpp
diff --git a/Source/WebKit/chromium/src/WebSettingsImpl.cpp b/Source/WebKit/chromium/src/WebSettingsImpl.cpp
index f6e63a6472f692b96a37644d19ad3d590bbe9fdf..27f7a91b420bed23a07c2a7890d8091df59ac90b 100644
--- a/Source/WebKit/chromium/src/WebSettingsImpl.cpp
+++ b/Source/WebKit/chromium/src/WebSettingsImpl.cpp
@@ -453,12 +453,16 @@ void WebSettingsImpl::setAcceleratedCompositingForVideoEnabled(bool enabled)
     m_settings->setAcceleratedCompositingForVideoEnabled(enabled);
 }
 
-void WebSettingsImpl::setAcceleratedCompositingForOverflowScrollEnabled(
-    bool enabled)
+void WebSettingsImpl::setAcceleratedCompositingForOverflowScrollEnabled(bool enabled)
 {
     m_settings->setAcceleratedCompositingForOverflowScrollEnabled(enabled);
 }
 
+void WebSettingsImpl::setAcceleratedCompositingForFixedRootBackgroundEnabled(bool enabled)
+{
+    m_settings->setAcceleratedCompositingForFixedRootBackgroundEnabled(enabled);
+}
+
 void WebSettingsImpl::setAcceleratedCompositingForPluginsEnabled(bool enabled)
 {
     m_settings->setAcceleratedCompositingForPluginsEnabled(enabled);