Move hardware and boot_control implementation to libupdate_engine.

The implementations of the BootControlInterface and HardwareInterface
are specific to the platform and use case. The delta_generator uses the
DeltaPerformer in the libpayload_consumer to apply a payload to a set
of partitions defined as local files, for example.

This patch move the platform implementations, not available when
building for the host back to the libupdate_engine.

Bug: 24619596
TEST=mma

Change-Id: I16ab06c2e53dfd046e693bdb7310ec26a2d69054
diff --git a/hardware_android.cc b/hardware_android.cc
new file mode 100644
index 0000000..a20fe6f
--- /dev/null
+++ b/hardware_android.cc
@@ -0,0 +1,113 @@
+//
+// Copyright (C) 2015 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 "update_engine/hardware_android.h"
+
+#include <base/files/file_util.h>
+#include <brillo/make_unique_ptr.h>
+#include <cutils/properties.h>
+
+#include "update_engine/common/hardware.h"
+#include "update_engine/common/platform_constants.h"
+
+using std::string;
+
+namespace chromeos_update_engine {
+
+namespace hardware {
+
+// Factory defined in hardware.h.
+std::unique_ptr<HardwareInterface> CreateHardware() {
+  return brillo::make_unique_ptr(new HardwareAndroid());
+}
+
+}  // namespace hardware
+
+// In Android there are normally three kinds of builds: eng, userdebug and user.
+// These builds target respectively a developer build, a debuggable version of
+// the final product and the pristine final product the end user will run.
+// Apart from the ro.build.type property name, they differ in the following
+// properties that characterize the builds:
+// * eng builds: ro.secure=0 and ro.debuggable=1
+// * userdebug builds: ro.secure=1 and ro.debuggable=1
+// * user builds: ro.secure=1 and ro.debuggable=0
+//
+// See IsOfficialBuild() and IsNormalMode() for the meaning of these options in
+// Android.
+
+bool HardwareAndroid::IsOfficialBuild() const {
+  // We run an official build iff ro.secure == 1, because we expect the build to
+  // behave like the end user product and check for updates. Note that while
+  // developers are able to build "official builds" by just running "make user",
+  // that will only result in a more restrictive environment. The important part
+  // is that we don't produce and push "non-official" builds to the end user.
+  //
+  // In case of a non-bool value, we take the most restrictive option and
+  // assume we are in an official-build.
+  return property_get_bool("ro.secure", 1) != 0;
+}
+
+bool HardwareAndroid::IsNormalBootMode() const {
+  // We are running in "dev-mode" iff ro.debuggable == 1. In dev-mode the
+  // update_engine will allow extra developers options, such as providing a
+  // different update URL. In case of error, we assume the build is in
+  // normal-mode.
+  return property_get_bool("ro.debuggable", 0) != 1;
+}
+
+bool HardwareAndroid::IsOOBEComplete(base::Time* out_time_of_oobe) const {
+  LOG(WARNING) << "STUB: Assuming OOBE is complete.";
+  if (out_time_of_oobe)
+    *out_time_of_oobe = base::Time();
+  return true;
+}
+
+string HardwareAndroid::GetHardwareClass() const {
+  LOG(WARNING) << "STUB: GetHardwareClass().";
+  return "ANDROID";
+}
+
+string HardwareAndroid::GetFirmwareVersion() const {
+  LOG(WARNING) << "STUB: GetFirmwareVersion().";
+  return "0";
+}
+
+string HardwareAndroid::GetECVersion() const {
+  LOG(WARNING) << "STUB: GetECVersion().";
+  return "0";
+}
+
+int HardwareAndroid::GetPowerwashCount() const {
+  LOG(WARNING) << "STUB: Assuming no factory reset was performed.";
+  return 0;
+}
+
+bool HardwareAndroid::GetNonVolatileDirectory(base::FilePath* path) const {
+  base::FilePath local_path(constants::kNonVolatileDirectory);
+  if (!base::PathExists(local_path)) {
+    LOG(ERROR) << "Non-volatile directory not found: " << local_path.value();
+    return false;
+  }
+  *path = local_path;
+  return true;
+}
+
+bool HardwareAndroid::GetPowerwashSafeDirectory(base::FilePath* path) const {
+  // On Android, we don't have a directory persisted across powerwash.
+  return false;
+}
+
+}  // namespace chromeos_update_engine