win: fix 'potentially uninitialized local variable' warnings

minidump/minidump_memory_writer_test.cc

 // Copyright 2014 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,
@@ skipping 70 matching lines @@
 
   minidump_file_writer.AddStream(memory_list_writer.Pass());
 
   StringFileWriter file_writer;
   ASSERT_TRUE(minidump_file_writer.WriteEverything(&file_writer));
 
   ASSERT_EQ(sizeof(MINIDUMP_HEADER) + sizeof(MINIDUMP_DIRECTORY) +
                 sizeof(MINIDUMP_MEMORY_LIST),
             file_writer.string().size());
 
-  const MINIDUMP_MEMORY_LIST* memory_list;
+  const MINIDUMP_MEMORY_LIST* memory_list = nullptr;
   ASSERT_NO_FATAL_FAILURE(
       GetMemoryListStream(file_writer.string(), &memory_list, 1));
 
   EXPECT_EQ(0u, memory_list->NumberOfMemoryRanges);
 }
 
 TEST(MinidumpMemoryWriter, OneMemoryRegion) {
   MinidumpFileWriter minidump_file_writer;
   auto memory_list_writer = make_scoped_ptr(new MinidumpMemoryListWriter());
 
   const uint64_t kBaseAddress = 0xfedcba9876543210;
   const uint64_t kSize = 0x1000;
   const uint8_t kValue = 'm';
 
   auto memory_writer = make_scoped_ptr(
       new TestMinidumpMemoryWriter(kBaseAddress, kSize, kValue));
   memory_list_writer->AddMemory(memory_writer.Pass());
 
   minidump_file_writer.AddStream(memory_list_writer.Pass());
 
   StringFileWriter file_writer;
   ASSERT_TRUE(minidump_file_writer.WriteEverything(&file_writer));
 
-  const MINIDUMP_MEMORY_LIST* memory_list;
+  const MINIDUMP_MEMORY_LIST* memory_list = nullptr;
   ASSERT_NO_FATAL_FAILURE(
       GetMemoryListStream(file_writer.string(), &memory_list, 1));
 
   MINIDUMP_MEMORY_DESCRIPTOR expected;
   expected.StartOfMemoryRange = kBaseAddress;
   expected.Memory.DataSize = kSize;
   expected.Memory.Rva =
       sizeof(MINIDUMP_HEADER) + sizeof(MINIDUMP_DIRECTORY) +
       sizeof(MINIDUMP_MEMORY_LIST) +
       memory_list->NumberOfMemoryRanges * sizeof(MINIDUMP_MEMORY_DESCRIPTOR);
@@ skipping 20 matching lines @@
   memory_list_writer->AddMemory(memory_writer_0.Pass());
   auto memory_writer_1 = make_scoped_ptr(
       new TestMinidumpMemoryWriter(kBaseAddress1, kSize1, kValue1));
   memory_list_writer->AddMemory(memory_writer_1.Pass());
 
   minidump_file_writer.AddStream(memory_list_writer.Pass());
 
   StringFileWriter file_writer;
   ASSERT_TRUE(minidump_file_writer.WriteEverything(&file_writer));
 
-  const MINIDUMP_MEMORY_LIST* memory_list;
+  const MINIDUMP_MEMORY_LIST* memory_list = nullptr;
   ASSERT_NO_FATAL_FAILURE(
       GetMemoryListStream(file_writer.string(), &memory_list, 1));
 
   EXPECT_EQ(2u, memory_list->NumberOfMemoryRanges);
 
   MINIDUMP_MEMORY_DESCRIPTOR expected;
 
   {
     SCOPED_TRACE("region 0");
 
@@ skipping 88 matching lines @@
 
   auto memory_writer = make_scoped_ptr(
       new TestMinidumpMemoryWriter(kBaseAddress1, kSize1, kValue1));
   memory_list_writer->AddMemory(memory_writer.Pass());
 
   minidump_file_writer.AddStream(memory_list_writer.Pass());
 
   StringFileWriter file_writer;
   ASSERT_TRUE(minidump_file_writer.WriteEverything(&file_writer));
 
-  const MINIDUMP_MEMORY_LIST* memory_list;
+  const MINIDUMP_MEMORY_LIST* memory_list = nullptr;
   ASSERT_NO_FATAL_FAILURE(
       GetMemoryListStream(file_writer.string(), &memory_list, 2));
 
   EXPECT_EQ(2u, memory_list->NumberOfMemoryRanges);
 
   MINIDUMP_MEMORY_DESCRIPTOR expected;
 
   {
     SCOPED_TRACE("region 0");
 
@@ skipping 57 matching lines @@
 
   auto memory_list_writer = make_scoped_ptr(new MinidumpMemoryListWriter());
   memory_list_writer->AddFromSnapshot(memory_snapshots);
 
   MinidumpFileWriter minidump_file_writer;
   minidump_file_writer.AddStream(memory_list_writer.Pass());
 
   StringFileWriter file_writer;
   ASSERT_TRUE(minidump_file_writer.WriteEverything(&file_writer));
 
-  const MINIDUMP_MEMORY_LIST* memory_list;
+  const MINIDUMP_MEMORY_LIST* memory_list = nullptr;
   ASSERT_NO_FATAL_FAILURE(
       GetMemoryListStream(file_writer.string(), &memory_list, 1));
 
   ASSERT_EQ(3u, memory_list->NumberOfMemoryRanges);
 
   for (size_t index = 0; index < memory_list->NumberOfMemoryRanges; ++index) {
     SCOPED_TRACE(base::StringPrintf("index %zu", index));
     ExpectMinidumpMemoryDescriptorAndContents(
         &expect_memory_descriptors[index],
         &memory_list->MemoryRanges[index],
         file_writer.string(),
         values[index],
         index == memory_list->NumberOfMemoryRanges - 1);
   }
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace crashpad