win: Add and use GET_FUNCTION() and GET_FUNCTION_REQUIRED()

snapshot/win/pe_image_reader_test.cc

 // Copyright 2015 The Crashpad Authors. All rights reserved.
 //
 // 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 "snapshot/win/pe_image_reader.h"
 
 #define PSAPI_VERSION 1
 #include <psapi.h>
 
 #include "gtest/gtest.h"
 #include "snapshot/win/process_reader_win.h"
+#include "util/win/get_function.h"
 
 extern "C" IMAGE_DOS_HEADER __ImageBase;
 
 namespace crashpad {
 namespace test {
 namespace {
 
 BOOL CrashpadGetModuleInformation(HANDLE process,
                           HMODULE module,
                           MODULEINFO* module_info,
                           DWORD cb) {
-  static decltype(GetModuleInformation)* get_module_information =
-      reinterpret_cast<decltype(GetModuleInformation)*>(
-          GetProcAddress(LoadLibrary(L"psapi.dll"), "GetModuleInformation"));
-  DCHECK(get_module_information);
+  static const auto get_module_information =
+      GET_FUNCTION_REQUIRED(L"psapi.dll", ::GetModuleInformation);
   return get_module_information(process, module, module_info, cb);
 }
 
 TEST(PEImageReader, DebugDirectory) {
   PEImageReader pe_image_reader;
   ProcessReaderWin process_reader;
   ASSERT_TRUE(process_reader.Initialize(GetCurrentProcess(),
                                         ProcessSuspensionState::kRunning));
   HMODULE self = reinterpret_cast<HMODULE>(&__ImageBase);
   MODULEINFO module_info;
@@ skipping 11 matching lines @@
   EXPECT_NE(std::string::npos, pdbname.find("crashpad_snapshot_test"));
   const std::string suffix(".pdb");
   EXPECT_EQ(
       0,
       pdbname.compare(pdbname.size() - suffix.size(), suffix.size(), suffix));
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace crashpad