[Composer] Create place holder for Composer 2.4.

Create place holder for composer 2.4.

Minor: Extend DisplayCapability to include protected contents.

BUG: 135929065
Test: build
Change-Id: I9dbdb21f4a69027bedd95cd54e9c3c652bbe9006
diff --git a/graphics/composer/2.4/utils/command-buffer/Android.bp b/graphics/composer/2.4/utils/command-buffer/Android.bp
new file mode 100644
index 0000000..8acf0e1
--- /dev/null
+++ b/graphics/composer/2.4/utils/command-buffer/Android.bp
@@ -0,0 +1,18 @@
+cc_library_headers {
+    name: "android.hardware.graphics.composer@2.4-command-buffer",
+    defaults: ["hidl_defaults"],
+    vendor_available: true,
+    shared_libs: [
+        "android.hardware.graphics.composer@2.4",
+    ],
+    export_shared_lib_headers: [
+        "android.hardware.graphics.composer@2.4",
+    ],
+    header_libs: [
+        "android.hardware.graphics.composer@2.3-command-buffer",
+    ],
+    export_header_lib_headers: [
+        "android.hardware.graphics.composer@2.3-command-buffer",
+    ],
+    export_include_dirs: ["include"],
+}
diff --git a/graphics/composer/2.4/utils/command-buffer/include/composer-command-buffer/2.4/ComposerCommandBuffer.h b/graphics/composer/2.4/utils/command-buffer/include/composer-command-buffer/2.4/ComposerCommandBuffer.h
new file mode 100644
index 0000000..6b64c16
--- /dev/null
+++ b/graphics/composer/2.4/utils/command-buffer/include/composer-command-buffer/2.4/ComposerCommandBuffer.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2019 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.
+ */
+
+#pragma once
+
+#ifndef LOG_TAG
+#warn "ComposerCommandBuffer.h included without LOG_TAG"
+#endif
+
+#undef LOG_NDEBUG
+#define LOG_NDEBUG 0
+
+#include <android/hardware/graphics/composer/2.4/IComposer.h>
+#include <android/hardware/graphics/composer/2.4/IComposerClient.h>
+#include <composer-command-buffer/2.3/ComposerCommandBuffer.h>
+
+namespace android {
+namespace hardware {
+namespace graphics {
+namespace composer {
+namespace V2_4 {
+
+using android::hardware::MessageQueue;
+using android::hardware::graphics::composer::V2_1::Error;
+using android::hardware::graphics::composer::V2_4::IComposerClient;
+
+// This class helps build a command queue.  Note that all sizes/lengths are in
+// units of uint32_t's.
+class CommandWriterBase : public V2_3::CommandWriterBase {
+  public:
+    CommandWriterBase(uint32_t initialMaxSize) : V2_3::CommandWriterBase(initialMaxSize) {}
+};
+
+// This class helps parse a command queue.  Note that all sizes/lengths are in
+// units of uint32_t's.
+class CommandReaderBase : public V2_3::CommandReaderBase {
+  public:
+    CommandReaderBase() : V2_3::CommandReaderBase(){};
+};
+
+}  // namespace V2_4
+}  // namespace composer
+}  // namespace graphics
+}  // namespace hardware
+}  // namespace android