Assign shared libraries stable package ids

When a shared library package is loaded into an AssetManager, the
shared library will be assigned a unique package id. Subsequent
AssetManaagers that load a shared library of the same package name
as the original shared library will use previously assigned package
name. Shared libraries will have stable package ids throughout the
lifetime of application.

Bug: 140790224
Bug: 128496033
Test: libandroidfw_tests
Test: third-party app no longer crashes on open
Test: atest CtsHostsideWebViewTests
Change-Id: Idc0315be21ea00b74d1a918b7083ad655104c008
diff --git a/libs/androidfw/DynamicLibManager.cpp b/libs/androidfw/DynamicLibManager.cpp
new file mode 100644
index 0000000..895b769
--- /dev/null
+++ b/libs/androidfw/DynamicLibManager.cpp
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 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.
+ */
+
+#include "androidfw/DynamicLibManager.h"
+
+namespace android {
+
+uint8_t DynamicLibManager::GetAssignedId(const std::string& library_package_name) {
+  auto lib_entry = shared_lib_package_ids_.find(library_package_name);
+  if (lib_entry != shared_lib_package_ids_.end()) {
+    return lib_entry->second;
+  }
+
+  return shared_lib_package_ids_[library_package_name] = next_package_id_++;
+}
+
+uint8_t DynamicLibManager::FindUnassignedId(uint8_t start_package_id) {
+  return (start_package_id < next_package_id_) ? next_package_id_ : start_package_id;
+}
+
+} // namespace android