Platform Window: Fixing null checks.

ui/platform_window/android/platform_window_android.cc

 // Copyright 2015 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 "ui/platform_window/android/platform_window_android.h"
 
 #include <android/input.h>
 #include <android/native_window_jni.h>
 
 #include "base/android/context_utils.h"
@@ skipping 44 matching lines @@
 PlatformWindowAndroid::PlatformWindowAndroid(PlatformWindowDelegate* delegate)
     : delegate_(delegate),
       window_(NULL),
       id_generator_(0),
       weak_factory_(this) {
 }
 
 PlatformWindowAndroid::~PlatformWindowAndroid() {
   if (window_)
     ReleaseWindow();
-  if (!java_platform_window_android_.is_empty()) {
-    JNIEnv* env = base::android::AttachCurrentThread();
-    Java_PlatformWindowAndroid_detach(
-        env, java_platform_window_android_.get(env).obj());
+  JNIEnv* env = base::android::AttachCurrentThread();
+  ScopedJavaLocalRef<jobject> scoped_obj =
+      java_platform_window_android_.get(env);
+  if (!scoped_obj.is_null()) {
+    Java_PlatformWindowAndroid_detach(env, scoped_obj.obj());
   }
 }
 
 void PlatformWindowAndroid::Destroy(JNIEnv* env, jobject obj) {
   delegate_->OnClosed();
 }
 
 void PlatformWindowAndroid::SurfaceCreated(JNIEnv* env,
                                            jobject obj,
                                            jobject jsurface,
@@ skipping 138 matching lines @@
 
 void PlatformWindowAndroid::ConfineCursorToBounds(const gfx::Rect& bounds) {
   NOTIMPLEMENTED();
 }
 
 PlatformImeController* PlatformWindowAndroid::GetPlatformImeController() {
   return &platform_ime_controller_;
 }
 
 }  // namespace ui