Always use arc::InstanceHolder<T>::GetInstanceForMethod

chrome/browser/chromeos/arc/arc_print_service.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/arc/arc_print_service.h"
 
 #include <utility>
 
 #include "ash/common/shell_delegate.h"
 #include "ash/common/wm_shell.h"
@@ skipping 49 matching lines @@
     : ArcService(bridge_service), binding_(this) {
   arc_bridge_service()->print()->AddObserver(this);
 }
 
 ArcPrintService::~ArcPrintService() {
   arc_bridge_service()->print()->RemoveObserver(this);
 }
 
 void ArcPrintService::OnInstanceReady() {
   mojom::PrintInstance* print_instance =
-      arc_bridge_service()->print()->instance();
-  if (!print_instance) {
-    LOG(ERROR) << "OnPrintInstanceReady called, but no print instance found";
-    return;
-  }
-
+      arc_bridge_service()->print()->GetInstanceForMethod("Init");
+  DCHECK(print_instance);
   print_instance->Init(binding_.CreateInterfacePtrAndBind());
 }
 
 void ArcPrintService::Print(mojo::ScopedHandle pdf_data) {
   if (!pdf_data.is_valid()) {
     LOG(ERROR) << "handle is invalid";
     return;
   }
 
   mojo::edk::ScopedPlatformHandle scoped_platform_handle;
   MojoResult mojo_result = mojo::edk::PassWrappedPlatformHandle(
       pdf_data.release().value(), &scoped_platform_handle);
   if (mojo_result != MOJO_RESULT_OK) {
     LOG(ERROR) << "PassWrappedPlatformHandle failed: " << mojo_result;
     return;
   }
 
   base::File file(scoped_platform_handle.release().handle);
 
   content::BrowserThread::PostTaskAndReplyWithResult(
       content::BrowserThread::FILE, FROM_HERE,
       base::Bind(&SavePdf, base::Passed(&file)), base::Bind(&OpenPdf));
 }
 
 }  // namespace arc