Mojo-ify implementation of screen orientation locking/unlocking.

content/browser/screen_orientation/screen_orientation.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 "content/browser/screen_orientation/screen_orientation.h"
+
+#include "base/bind.h"
+#include "content/public/browser/navigation_details.h"
+#include "content/public/browser/screen_orientation_provider.h"
+#include "content/public/browser/web_contents.h"
+
+namespace content {
+
+using LockResult = ::blink::mojom::ScreenOrientationLockResult;
+
+ScreenOrientation::ScreenOrientation(WebContents* web_contents)
+    : WebContentsObserver(web_contents),
+      bindings_(web_contents, this),
+      weak_factory_(this) {
+  provider_.reset(new ScreenOrientationProvider(web_contents));
+}
+
+ScreenOrientation::~ScreenOrientation() = default;
+
+void ScreenOrientation::LockOrientation(
+    blink::WebScreenOrientationLockType orientation,
+    const LockOrientationCallback& callback) {
+  if (!on_result_callback_.is_null()) {
+    NotifyLockResult(
+        LockResult::SCREEN_ORIENTATION_LOCK_RESULT_ERROR_CANCELED);
+  }
+
+  on_result_callback_ = callback;
+
+  if (!provider_) {
+    NotifyLockResult(
+        LockResult::SCREEN_ORIENTATION_LOCK_RESULT_ERROR_NOT_AVAILABLE);
+    return;
+  }
+
+  provider_->LockOrientation(orientation,
+                             base::Bind(&ScreenOrientation::NotifyLockResult,
+                                        base::Unretained(this)));
+}
+
+void ScreenOrientation::UnlockOrientation() {
+  // Cancel any pending lock request.
+  NotifyLockResult(
+      LockResult::SCREEN_ORIENTATION_LOCK_RESULT_ERROR_CANCELED);
+
+  if (provider_)
+    provider_->UnlockOrientation();
+}
+
+void ScreenOrientation::DidNavigateMainFrame(
+    const LoadCommittedDetails& details,
+    const FrameNavigateParams& params) {
+  if (!provider_ || details.is_in_page)
+    return;
+  provider_->UnlockOrientation();
+}
+
+void ScreenOrientation::NotifyLockResult(LockResult result) {
+  if (on_result_callback_.is_null())
+    return;
+
+  on_result_callback_.Run(result);
+  // Reset the callback.
+  on_result_callback_ = LockOrientationCallback();

[mlamouri (slow - plz ping), 2016/11/13 00:26:35]

`base::ResetAndReturn(&on_result_callback_).Run(result);` maybe?

[lunalu1, 2016/11/16 18:46:58]

Done.

+}
+
+ScreenOrientationProvider* ScreenOrientation::GetScreenOrientationProvider() {
+  return provider_.get();
+}
+
+}  // namespace content