Centralize ScreenOrientationProvider logic, add platform delegates

content/public/browser/screen_orientation_provider.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_SCREEN_ORIENTATION_PROVIDER_H_
 #define CONTENT_PUBLIC_BROWSER_SCREEN_ORIENTATION_PROVIDER_H_
 
 #include "base/macros.h"
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebScreenOrientationLockType.h"
 
 namespace content {
 
 class ScreenOrientationDispatcherHost;
+class ScreenOrientationProviderFactory;
 class WebContents;
 
 // Interface that needs to be implemented by any backend that wants to handle
 // screen orientation lock/unlock.
 class CONTENT_EXPORT ScreenOrientationProvider {
  public:
   // Lock the screen orientation to |orientations|.
   virtual void LockOrientation(
       int request_id,
       blink::WebScreenOrientationLockType orientations) = 0;
 
   // Unlock the screen orientation.
   virtual void UnlockOrientation() = 0;
 
   // Inform about a screen orientation update. It is called to let the provider
   // know if a lock has been resolved.
   virtual void OnOrientationChange() = 0;
 
   virtual ~ScreenOrientationProvider() {}
 
+  // Creates a ScreenOrientationProvider for a ScreenOrientationDispatcherHost
+  // to notify. SetFactory can be used to override.
+  static ScreenOrientationProvider* Create(

[mlamouri (slow - plz ping), 2014/09/16 20:21:04]

Should that be an own ptr?

[jonross, 2014/09/16 21:48:13]

Doing a code search for 'own ptr' points me to wtf::ownptr which is used heavily
in third_party/WebKit

Is there an equivalent being used within the content/ package?

[mlamouri (slow - plz ping), 2014/09/16 22:00:45]

Sorry about that. I got confused with WebKit indeed ;)

You can return a scoped_ptr<ScreenOrientationProvider> to mark that the caller
owns the returned pointer. It will prevent accidental leaks too.

+      ScreenOrientationDispatcherHost* dispatcher_host,
+      WebContents* web_contents);
+
+  // Provide a factory to override the creation in Create(). The factory is not
+  // owned by ScreenOrientationProvider.
+  static void SetFactory(ScreenOrientationProviderFactory* factory);
+
  protected:
   friend class ScreenOrientationDispatcherHostImpl;
 
-  static ScreenOrientationProvider* Create(
-      ScreenOrientationDispatcherHost* dispatcher_host,
-      WebContents* web_contents);
+  ScreenOrientationProvider() {}
 
-  ScreenOrientationProvider() {}
+ private:
+  // Not owned, overrides behaviour in Create().
+  static ScreenOrientationProviderFactory* factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenOrientationProvider);
 };
 
-#if !defined(OS_ANDROID)
-// static
-ScreenOrientationProvider* ScreenOrientationProvider::Create(
-    ScreenOrientationDispatcherHost* dispatcher_host,
-    WebContents* web_contents) {
-  return NULL;
-}
-#endif // !defined(OS_ANDROID)
-
 } // namespace content
 
 #endif // CONTENT_PUBLIC_BROWSER_SCREEN_ORIENTATION_PROVIDER_H_