drm_hwcomposer: use CamelCase in source/header files related to class

Main goal is to increase readability of file names.
AOSP uses camelcase for files in many projects.
Lets do the same for drm_hwcomposer.

Keep platform/ directory as is, since class names is different from file names.

Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>
Change-Id: I7e992357851c2a86711f4da1241c4d507359e56b
diff --git a/backend/BackendClient.cpp b/backend/BackendClient.cpp
new file mode 100644
index 0000000..033a35c
--- /dev/null
+++ b/backend/BackendClient.cpp
@@ -0,0 +1,35 @@
+/*
+ * 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.
+ */
+
+#include "BackendClient.h"
+
+#include "BackendManager.h"
+
+namespace android {
+
+HWC2::Error BackendClient::ValidateDisplay(DrmHwcTwo::HwcDisplay *display,
+                                           uint32_t *num_types,
+                                           uint32_t * /*num_requests*/) {
+  for (auto & [ layer_handle, layer ] : display->layers()) {
+    layer.set_validated_type(HWC2::Composition::Client);
+    ++*num_types;
+  }
+  return HWC2::Error::HasChanges;
+}
+
+REGISTER_BACKEND("client", BackendClient);
+
+}  // namespace android