drm_hwcomposer: refactor platform directory

Motivation:

Platform term meaning used in drm_hwcomposer does not correspond to the
content of the platform directory. Platform directory consists of:
1. Buffer information getters for different gralloc (currently called platform).
2. Composition planner logic (which has flaws and should be reworked into
   layer->plane mapping during validation stage logic).
3. DrmGenericImpoter with reference counting logic.

Android-11 IMapper@4 metadata API offers a generic way to access buffer
information which makes other gralloc buffer information getters obsolete.
Legacy getters should be maintained for some time until all known users
will migrate to Mapper@4 API.

Implementation:

1. Split 'PlatformImporter' logic to 'Importer' only and 'Buffer Getter' logic.
   a. Remove buffer_handle_t parameter from ImportBuffer(). Instead user should
      get BufferInfo using ConvertBoInfo to struct hwc_drm_bo_t, then use it for
      ImportBuffer().
   b. Move DrmGenericImporter.{cpp/h} into the drm directory.

2. Isolate planner code in single file and move it to compositor directory as
   compositor/Planner.{cpp/h}

3. Rename platform definition
   a. Rename platform directory to bufferinfo.
   b. Rename/move bufferinfo/platorm*.{cpp,h} getters to
      bufferinfo/legacy/BufferInfo*.{cpp,h}. Align class names/includes.

4. Split legacy/metadata getters logic.
   a. Apply existing bufferinfogetter base class only for legacy getters.
   b. Combine legacy/generic gettera under new base class.
   c. Create a placeholder for generic(metadata) getter.

Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>
diff --git a/bufferinfo/BufferInfoGetter.h b/bufferinfo/BufferInfoGetter.h
new file mode 100644
index 0000000..78c29ff
--- /dev/null
+++ b/bufferinfo/BufferInfoGetter.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_BUFFERINFOGETTER_H_
+#define ANDROID_BUFFERINFOGETTER_H_
+
+#include <drm/drm_fourcc.h>
+#include <hardware/gralloc.h>
+
+#include "drm/DrmDevice.h"
+#include "drmhwcgralloc.h"
+
+#ifndef DRM_FORMAT_INVALID
+#define DRM_FORMAT_INVALID 0
+#endif
+
+namespace android {
+
+class BufferInfoGetter {
+ public:
+  virtual ~BufferInfoGetter() {
+  }
+
+  virtual int ConvertBoInfo(buffer_handle_t handle, hwc_drm_bo_t *bo) = 0;
+
+  bool IsHandleUsable(buffer_handle_t handle);
+
+  static BufferInfoGetter *GetInstance();
+
+  static uint32_t DrmFormatToBitsPerPixel(uint32_t drm_format);
+  static bool IsDrmFormatRgb(uint32_t drm_format);
+};
+
+class LegacyBufferInfoGetter : public BufferInfoGetter {
+ public:
+  using BufferInfoGetter::BufferInfoGetter;
+
+  int Init();
+
+  int ConvertBoInfo(buffer_handle_t handle, hwc_drm_bo_t *bo) override = 0;
+
+  static LegacyBufferInfoGetter *CreateInstance();
+
+  static uint32_t ConvertHalFormatToDrm(uint32_t hal_format);
+  const gralloc_module_t *gralloc_;
+};
+
+#define LEGACY_BUFFER_INFO_GETTER(getter_)                           \
+  LegacyBufferInfoGetter *LegacyBufferInfoGetter::CreateInstance() { \
+    auto *instance = new getter_();                                  \
+    if (!instance)                                                   \
+      return NULL;                                                   \
+                                                                     \
+    int ret = instance->Init();                                      \
+    if (ret) {                                                       \
+      ALOGE("Failed to initialize the " #getter_ " getter %d", ret); \
+      delete instance;                                               \
+      return NULL;                                                   \
+    }                                                                \
+    return instance;                                                 \
+  }
+
+}  // namespace android
+#endif