VR: Create VR implementation for HWC HIDL interface

* Implement the IComposerClient interface for a VR HWC.
* Introduce new command to send layer information to the VR HWC.
* Add observer interface in the VR HWC service allowing VR Window
  Manager to consume SurfaceFlinger output.

Bug: 32541196, 33297385
Test: Compiled and ran with modified surfaceflinger that connects to the
VR hwcomposer and made sure there are no crashes.

Change-Id: Ic2c882ba5e4c570cbd0b7a180845a5e61a768cad
diff --git a/services/vr/vr_window_manager/composer/impl/vr_composer_client.cpp b/services/vr/vr_window_manager/composer/impl/vr_composer_client.cpp
new file mode 100644
index 0000000..367acb7
--- /dev/null
+++ b/services/vr/vr_window_manager/composer/impl/vr_composer_client.cpp
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2016 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 <android/dvr/composer/1.0/IVrComposerClient.h>
+#include <hardware/gralloc.h>
+#include <hardware/gralloc1.h>
+#include <log/log.h>
+
+#include "vr_hwc.h"
+#include "vr_composer_client.h"
+
+namespace android {
+namespace dvr {
+
+using android::hardware::graphics::common::V1_0::PixelFormat;
+using android::dvr::composer::V1_0::IVrComposerClient;
+
+VrComposerClient::VrComposerClient(dvr::VrHwc& hal)
+    : ComposerClient(hal), mVrHal(hal) {}
+
+VrComposerClient::~VrComposerClient() {}
+
+std::unique_ptr<ComposerClient::CommandReader>
+VrComposerClient::createCommandReader() {
+  return std::unique_ptr<CommandReader>(new VrCommandReader(*this));
+}
+
+VrComposerClient::VrCommandReader::VrCommandReader(VrComposerClient& client)
+    : CommandReader(client), mVrClient(client), mVrHal(client.mVrHal) {}
+
+VrComposerClient::VrCommandReader::~VrCommandReader() {}
+
+bool VrComposerClient::VrCommandReader::parseCommand(
+    IComposerClient::Command command, uint16_t length) {
+  IVrComposerClient::VrCommand vrCommand =
+      static_cast<IVrComposerClient::VrCommand>(command);
+  switch (vrCommand) {
+    case IVrComposerClient::VrCommand::SET_LAYER_INFO:
+      return parseSetLayerInfo(length);
+    default:
+      return CommandReader::parseCommand(command, length);
+  }
+}
+
+bool VrComposerClient::VrCommandReader::parseSetLayerInfo(uint16_t length) {
+  if (length != 2) {
+    return false;
+  }
+
+  auto err = mVrHal.setLayerInfo(mDisplay, mLayer, read(), read());
+  if (err != Error::NONE) {
+    mWriter.setError(getCommandLoc(), err);
+  }
+
+  return true;
+}
+
+}  // namespace dvr
+}  // namespace android