Revert of Replace system IO calls in chromecast/crash with Chrome utilities. (patchset #9 id:160001 of https://codereview.chromium.org/1227963002/)

Reason for revert:
Breaks CastCrashReporterClientTest.EndToEndTestOnIORestrictedThread:

https://build.chromium.org/p/chromium.linux/builders/Cast%20Linux/builds/2709

Original issue's description:
> Replace system IO calls in chromecast/crash with Chrome utilities.
>
> System IO calls had been used to avoid thread IO restrictions in the
> crash handler. This change replaces each of these calls with the more
> platform-independent, stable Chrome IO utilities from ::base. Thread
> restrictions are disabled in crash_util.cc.
>
> BUG= b/22329428
>
> Committed: https://crrev.com/4927df40d0342522fc268f884835b43f9004549e
> Cr-Commit-Position: refs/heads/master@{#339161}

TBR=wzhong@chromium.org,bcf@google.com,gunsch@chromium.org,gfhuang@chromium.org,slan@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= b/22329428

Review URL: https://codereview.chromium.org/1239083005

Cr-Commit-Position: refs/heads/master@{#339183}

1 files changed, 85 insertions, 5 deletions

diff --git a/chromecast/crash/linux/dummy_minidump_generator_unittest.cc b/chromecast/crash/linux/dummy_minidump_generator_unittest.cc
index d70ea76..c38304f 100644
--- a/chromecast/crash/linux/dummy_minidump_generator_unittest.cc
+++ b/chromecast/crash/linux/dummy_minidump_generator_unittest.cc
@@ -11,6 +11,12 @@
 
 namespace chromecast {
 
+namespace {
+// This value should stay in sync with the internal buffer size used in
+// CopyAndDelete().
+const int kInternalBufferSize = 32768;
+}  // namespace
+
 TEST(DummyMinidumpGeneratorTest, GenerateFailsWithInvalidPath) {
   // Create directory in which to put minidump.
   base::FilePath minidump_dir;
@@ -21,7 +27,7 @@ TEST(DummyMinidumpGeneratorTest, GenerateFailsWithInvalidPath) {
   ASSERT_FALSE(generator.Generate(minidump_dir.Append("minidump.dmp").value()));
 }
 
-TEST(DummyMinidumpGeneratorTest, GenerateSucceedsWithSmallSource) {
+TEST(DummyMinidumpGeneratorTest, GenerateSucceedsWithValidPath) {
   // Create directory in which to put minidump.
   base::FilePath minidump_dir;
   ASSERT_TRUE(base::CreateNewTempDirectory("", &minidump_dir));
@@ -46,24 +52,98 @@ TEST(DummyMinidumpGeneratorTest, GenerateSucceedsWithSmallSource) {
   EXPECT_EQ(data, copied_data);
 }
 
-TEST(DummyMinidumpGeneratorTest, GenerateSucceedsWithLargeSource) {
+TEST(DummyMinidumpGeneratorTest, CopyAndDeleteFailsWithInvalidSource) {
+  // Create directory in which to put minidump.
+  base::FilePath minidump_dir;
+  ASSERT_TRUE(base::CreateNewTempDirectory("", &minidump_dir));
+
+  // Attempt to copy from an invalid path.
+  DummyMinidumpGenerator generator("/path/does/not/exist/minidump.dmp");
+  ASSERT_FALSE(generator.CopyAndDeleteForTest(
+      minidump_dir.Append("minidump.dmp").value()));
+}
+
+TEST(DummyMinidumpGeneratorTest, CopyAndDeleteSucceedsWithSmallSource) {
+  // Create directory in which to put minidump.
+  base::FilePath minidump_dir;
+  ASSERT_TRUE(base::CreateNewTempDirectory("", &minidump_dir));
+
+  // Create a fake minidump file.
+  base::FilePath fake_minidump;
+  ASSERT_TRUE(base::CreateTemporaryFile(&fake_minidump));
+  const std::string data("Test contents of the minidump file.\n");
+  ASSERT_EQ(static_cast<int>(data.size()),
+            base::WriteFile(fake_minidump, data.c_str(), data.size()));
+
+  base::FilePath new_minidump = minidump_dir.Append("minidump.dmp");
+  DummyMinidumpGenerator generator(fake_minidump.value());
+  ASSERT_TRUE(generator.CopyAndDeleteForTest(new_minidump.value()));
+
+  // Original file should not exist, and new file should contain original
+  // contents.
+  std::string copied_data;
+  EXPECT_FALSE(base::PathExists(fake_minidump));
+  ASSERT_TRUE(base::PathExists(new_minidump));
+  EXPECT_TRUE(base::ReadFileToString(new_minidump, &copied_data));
+  EXPECT_EQ(data, copied_data);
+}
+
+TEST(DummyMinidumpGeneratorTest, CopyAndDeleteSucceedsWithLargeSource) {
+  // Create directory in which to put minidump.
+  base::FilePath minidump_dir;
+  ASSERT_TRUE(base::CreateNewTempDirectory("", &minidump_dir));
+
+  // Create a large fake minidump file.
+  // Note: The file must be greater than the size of the buffer used to copy the
+  // file in CopyAndDelete(). Create a big string in memory.
+  base::FilePath fake_minidump;
+  ASSERT_TRUE(base::CreateTemporaryFile(&fake_minidump));
+  size_t str_len = kInternalBufferSize * 10 + 1;
+  const std::string data = base::RandBytesAsString(str_len);
+
+  // Write the string to the file and verify that the file is big enough.
+  ASSERT_EQ(static_cast<int>(data.size()),
+            base::WriteFile(fake_minidump, data.c_str(), data.size()));
+  int64_t filesize = 0;
+  ASSERT_TRUE(base::GetFileSize(fake_minidump, &filesize));
+  ASSERT_GT(filesize, kInternalBufferSize);
+
+  base::FilePath new_minidump = minidump_dir.Append("minidump.dmp");
+  DummyMinidumpGenerator generator(fake_minidump.value());
+  ASSERT_TRUE(generator.CopyAndDeleteForTest(new_minidump.value()));
+
+  // Original file should not exist, and new file should contain original
+  // contents.
+  std::string copied_data;
+  EXPECT_FALSE(base::PathExists(fake_minidump));
+  ASSERT_TRUE(base::PathExists(new_minidump));
+  EXPECT_TRUE(base::ReadFileToString(new_minidump, &copied_data));
+  EXPECT_EQ(data, copied_data);
+}
+
+TEST(DummyMinidumpGeneratorTest, CopyAndDeleteSucceedsWhenEOFAlignsWithBuffer) {
   // Create directory in which to put minidump.
   base::FilePath minidump_dir;
   ASSERT_TRUE(base::CreateNewTempDirectory("", &minidump_dir));
 
   // Create a large fake minidump file.
+  // Note: The file must be greater than the size of the buffer used to copy the
+  // file in CopyAndDelete(). Create a big string in memory.
   base::FilePath fake_minidump;
   ASSERT_TRUE(base::CreateTemporaryFile(&fake_minidump));
-  size_t str_len = 32768 * 10 + 1;
+  size_t str_len = kInternalBufferSize;
   const std::string data = base::RandBytesAsString(str_len);
 
-  // Write the string to the file.
+  // Write the string to the file and verify that the file is big enough.
   ASSERT_EQ(static_cast<int>(data.size()),
             base::WriteFile(fake_minidump, data.c_str(), data.size()));
+  int64_t filesize = 0;
+  ASSERT_TRUE(base::GetFileSize(fake_minidump, &filesize));
+  ASSERT_EQ(kInternalBufferSize, filesize);
 
   base::FilePath new_minidump = minidump_dir.Append("minidump.dmp");
   DummyMinidumpGenerator generator(fake_minidump.value());
-  ASSERT_TRUE(generator.Generate(new_minidump.value()));
+  ASSERT_TRUE(generator.CopyAndDeleteForTest(new_minidump.value()));
 
   // Original file should not exist, and new file should contain original
   // contents.