Add allocator interface for use by cdm_adapter

media/cdm/simple_cdm_allocator.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 "media/cdm/simple_cdm_allocator.h"
+
+#include "media/base/video_frame.h"
+#include "media/cdm/cdm_helpers.h"
+#include "media/cdm/simple_cdm_buffer.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace media {
+
+namespace {
+
+class SimpleCdmVideoFrame : public VideoFrameImpl {
+ public:
+  SimpleCdmVideoFrame() {}
+  ~SimpleCdmVideoFrame() final {}
+
+  // VideoFrameImpl implementation.
+  scoped_refptr<media::VideoFrame> TransformToVideoFrame(
+      gfx::Size natural_size) final {
+    DCHECK(FrameBuffer());
+
+    cdm::Buffer* buffer = FrameBuffer();
+    gfx::Size frame_size(Size().width, Size().height);
+    scoped_refptr<media::VideoFrame> frame =
+        media::VideoFrame::WrapExternalYuvData(
+            PIXEL_FORMAT_YV12, frame_size, gfx::Rect(frame_size), natural_size,
+            Stride(kYPlane), Stride(kUPlane), Stride(kVPlane),
+            buffer->Data() + PlaneOffset(kYPlane),
+            buffer->Data() + PlaneOffset(kUPlane),
+            buffer->Data() + PlaneOffset(kVPlane),
+            base::TimeDelta::FromMicroseconds(Timestamp()));
+
+    // The FrameBuffer needs to remain around until |frame| is destroyed.
+    frame->AddDestructionObserver(
+        base::Bind(&cdm::Buffer::Destroy, base::Unretained(buffer)));
+
+    // Clear FrameBuffer so that SimpleCdmVideoFrame no longer has a reference
+    // to it.
+    SetFrameBuffer(nullptr);
+    return frame;
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SimpleCdmVideoFrame);
+};
+
+}  // namespace
+
+SimpleCdmAllocator::SimpleCdmAllocator() {}
+
+SimpleCdmAllocator::~SimpleCdmAllocator() {}
+
+// Creates a new SimpleCdmBuffer on every request. It does not keep track of
+// the memory allocated, so the caller is responsible for calling Destroy()
+// on the buffer when it is no longer needed.
+cdm::Buffer* SimpleCdmAllocator::CreateCdmBuffer(uint32_t capacity) {
+  if (!capacity)
+    return nullptr;
+
+  return SimpleCdmBuffer::Create(capacity);
+}
+
+// Creates a new SimpleCdmVideoFrame on every request.
+scoped_ptr<VideoFrameImpl> SimpleCdmAllocator::CreateCdmVideoFrame() {
+  return make_scoped_ptr(new SimpleCdmVideoFrame());
+}
+
+}  // namespace media