Enable display rotation, magnifier in unified desktop mode

ash/host/transformer_helper.cc

Index: ash/host/transformer_helper.cc
diff --git a/ash/host/transformer_helper.cc b/ash/host/transformer_helper.cc
index 8075fc394e5505ff98c514308b49452db77dcaf3..af56d8a8d64fdaa2c38e26e9289ad7d9d8fab353 100644
--- a/ash/host/transformer_helper.cc
+++ b/ash/host/transformer_helper.cc
@@ -58,11 +58,14 @@ class SimpleRootWindowTransformer : public RootWindowTransformer {
 
 TransformerHelper::TransformerHelper(AshWindowTreeHost* ash_host)
     : ash_host_(ash_host) {
-  SetTransform(gfx::Transform());
 }
 
 TransformerHelper::~TransformerHelper() {}
 
+void TransformerHelper::Init() {
+  SetTransform(gfx::Transform());
+}
+
 gfx::Insets TransformerHelper::GetHostInsets() const {
   return transformer_->GetHostInsets();
 }