Add CdmFileIOProvider interface for use by cdm_adapter

media/cdm/cdm_adapter.h

 // 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.
 
 #ifndef MEDIA_CDM_CDM_ADAPTER_H_
 #define MEDIA_CDM_CDM_ADAPTER_H_
 
 #include <stdint.h>
 
+#include <memory>
 #include <string>
 #include <vector>
 
+#include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_native_library.h"
 #include "base/threading/thread.h"
 #include "media/base/cdm_config.h"
 #include "media/base/cdm_context.h"
 #include "media/base/cdm_factory.h"
 #include "media/base/cdm_promise_adapter.h"
 #include "media/base/decryptor.h"
 #include "media/base/media_export.h"
 #include "media/base/media_keys.h"
 #include "media/cdm/api/content_decryption_module.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace media {
 
 class AudioFramesImpl;
 class CdmAllocator;
+class CdmFileIO;
 class CdmWrapper;
 
+// Called when the CDM needs a FileIO object from the host to do file IO
+// operations. Returns NULL if a FileIO object cannot be obtained. Once a
+// valid FileIO object is returned, |client| must be valid until
+// FileIO::Close() is called. The CDM can call this method multiple times
+// to operate on different files.
+using CdmFileIOProviderCB =

[xhwang, 2016/04/18 21:09:22]

The naming is a bit odd since the callback does create a "Provider". 

Typically we call this a Create*CB, e.g. CreateCdmFileIOCB:

https://code.google.com/p/chromium/codesearch#search/&q=Create.*CB&sq=package...

[jrummell, 2016/04/19 23:59:29]

Done.

+    base::Callback<std::unique_ptr<CdmFileIO>(cdm::FileIOClient* client)>;
+
 class MEDIA_EXPORT CdmAdapter : public MediaKeys,
                                 public CdmContext,
                                 public Decryptor,
                                 NON_EXPORTED_BASE(public cdm::Host_7),
                                 NON_EXPORTED_BASE(public cdm::Host_8) {
  public:
   // Create the CDM using |cdm_path| and initialize it using |key_system| and
   // |cdm_config|. |allocator| is to be used whenever the CDM needs memory
-  // and to create VideoFrames. Callbacks will be used for events generated
-  // by the CDM. |cdm_created_cb| will be called when the CDM is loaded and
-  // initialized.
+  // and to create VideoFrames. |file_io_provider| is to be used whenever the
+  // CDM needs access to the file system. Callbacks will be used for events
+  // generated by the CDM. |cdm_created_cb| will be called when the CDM is
+  // loaded and initialized.
   static void Create(
       const std::string& key_system,
       const base::FilePath& cdm_path,
       const CdmConfig& cdm_config,
       scoped_ptr<CdmAllocator> allocator,
+      const CdmFileIOProviderCB& file_io_provider_cb,
       const SessionMessageCB& session_message_cb,
       const SessionClosedCB& session_closed_cb,
       const LegacySessionErrorCB& legacy_session_error_cb,
       const SessionKeysChangeCB& session_keys_change_cb,
       const SessionExpirationUpdateCB& session_expiration_update_cb,
       const CdmCreatedCB& cdm_created_cb);
 
   // MediaKeys implementation.
   void SetServerCertificate(const std::vector<uint8_t>& certificate,
                             scoped_ptr<SimpleCdmPromise> promise) final;
@@ skipping 79 matching lines @@
   void EnableOutputProtection(uint32_t desired_protection_mask) override;
   void QueryOutputProtectionStatus() override;
   void OnDeferredInitializationDone(cdm::StreamType stream_type,
                                     cdm::Status decoder_status) override;
   cdm::FileIO* CreateFileIO(cdm::FileIOClient* client) override;
 
  private:
   CdmAdapter(const std::string& key_system,
              const CdmConfig& cdm_config,
              scoped_ptr<CdmAllocator> allocator,
+             const CdmFileIOProviderCB& file_io_provider_cb,
              const SessionMessageCB& session_message_cb,
              const SessionClosedCB& session_closed_cb,
              const LegacySessionErrorCB& legacy_session_error_cb,
              const SessionKeysChangeCB& session_keys_change_cb,
              const SessionExpirationUpdateCB& session_expiration_update_cb);
   ~CdmAdapter() final;
 
   // Load the CDM using |cdm_path| and initialize it. |promise| is resolved if
   // the CDM is successfully loaded and initialized, rejected otherwise.
   void Initialize(const base::FilePath& cdm_path,
@@ skipping 41 matching lines @@
 
   // Keep track of video frame natural size from the latest configuration
   // as the CDM doesn't provide it.
   gfx::Size natural_size_;
 
   // Keep track of audio parameters.
   int audio_samples_per_second_;
   ChannelLayout audio_channel_layout_;
 
   scoped_ptr<CdmAllocator> allocator_;
+  CdmFileIOProviderCB file_io_provider_cb_;
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<CdmAdapter> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CdmAdapter);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CDM_CDM_ADAPTER_H_