Mojo-ify implementation of screen orientation locking/unlocking.

content/public/browser/screen_orientation_provider.h

Index: content/public/browser/screen_orientation_provider.h
diff --git a/content/public/browser/screen_orientation_provider.h b/content/public/browser/screen_orientation_provider.h
index 463fc82786656d2d6a74d4b739779d09a230a1f8..2ea29127eabcde72829c7783a9b9767cabf56dad 100644
--- a/content/public/browser/screen_orientation_provider.h
+++ b/content/public/browser/screen_orientation_provider.h
@@ -7,28 +7,33 @@
 
 #include <memory>
 
+#include "base/callback.h"
 #include "base/macros.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "third_party/WebKit/public/platform/modules/screen_orientation/WebScreenOrientationLockType.h"
+#include "third_party/WebKit/public/platform/modules/screen_orientation/screen_orientation.mojom.h"
 
 namespace content {
 
 class ScreenOrientationDelegate;
-class ScreenOrientationDispatcherHost;
 class WebContents;
 
+using LockOrientationCallback =
+    base::Callback<void(::blink::mojom::ScreenOrientationLockResult)>;
+
 // Handles screen orientation lock/unlock. Platforms which wish to provide
 // custom implementations can provide a factory for ScreenOrientationDelegate.
 class CONTENT_EXPORT ScreenOrientationProvider : public WebContentsObserver {
  public:
-  ScreenOrientationProvider(ScreenOrientationDispatcherHost* dispatcher_host,
-                            WebContents* web_contents);
+  ScreenOrientationProvider(WebContents* web_contents);
+
   ~ScreenOrientationProvider() override;
 
-  // Lock the screen orientation to |orientations|.
-  void LockOrientation(int request_id,
-                       blink::WebScreenOrientationLockType lock_orientation);
+  // Lock the screen orientation to |orientation|, |callback| is the callback
+  // that should be invoked when this request receives a result.
+  void LockOrientation(blink::WebScreenOrientationLockType orientation,
+                       const LockOrientationCallback& callback);
 
   // Unlock the screen orientation.
   void UnlockOrientation();
@@ -46,11 +51,9 @@ class CONTENT_EXPORT ScreenOrientationProvider : public WebContentsObserver {
                                      bool will_cause_resize) override;
 
  private:
-  struct LockInformation {
-    LockInformation(int request_id, blink::WebScreenOrientationLockType lock);
-    int request_id;
-    blink::WebScreenOrientationLockType lock;
-  };
+  // Calls on |on_result_callback_| with |result|, followed by resetting
+  // |on_result_callback_| and |pending_lock_orientation_|.
+  void NotifyLockResult(::blink::mojom::ScreenOrientationLockResult result);
 
   // Returns the lock type that should be associated with 'natural' lock.
   // Returns WebScreenOrientationLockDefault if the natural lock type can't be
@@ -64,15 +67,15 @@ class CONTENT_EXPORT ScreenOrientationProvider : public WebContentsObserver {
   // Not owned, responsible for platform implementations.
   static ScreenOrientationDelegate* delegate_;
 
-  // ScreenOrientationDispatcherHost owns ScreenOrientationProvider.
-  ScreenOrientationDispatcherHost* dispatcher_;
-
   // Whether the ScreenOrientationProvider currently has a lock applied.
   bool lock_applied_;
 
   // Locks that require orientation changes are not completed until
   // OnOrientationChange.
-  std::unique_ptr<LockInformation> pending_lock_;
+
+  blink::WebScreenOrientationLockType pending_lock_orientation_;

[mlamouri (slow - plz ping), 2016/11/13 00:26:36]

I would feel slightly more comfortable having
base::Optional<blink::WebScreenOrientationLockType> because it would be
semantically clearer instead of using "Default" but both would be correct so
take this as a suggestion ;)

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

Done.

+
+  LockOrientationCallback on_result_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenOrientationProvider);
 };