Remove usage of compat from client

When used in client headers, the downstream dependency on compat
is unpleasant, so avoid that.

This is another alternative rather than
https://codereview.chromium.org/1424443002/.

R=mark@chromium.org
BUG=chromium:546288, crashpad:1

Review URL: https://codereview.chromium.org/1419673007 .

client/client.gyp

@@ -21,7 +21,6 @@
       'target_name': 'crashpad_client',
       'type': 'static_library',
       'dependencies': [
-        '../compat/compat.gyp:crashpad_compat',
         '../third_party/mini_chromium/mini_chromium.gyp:base',
         '../util/util.gyp:crashpad_util',
       ],

client/client_test.gyp

@@ -22,7 +22,6 @@
       'type': 'executable',
       'dependencies': [
         'client.gyp:crashpad_client',
-        '../compat/compat.gyp:crashpad_compat',
         '../test/test.gyp:crashpad_test',
         '../third_party/gmock/gmock.gyp:gmock',
         '../third_party/gtest/gtest.gyp:gtest',

util/file/file_io.h

@@ -67,11 +67,14 @@ using ScopedFileHandle = base::ScopedFD;
 //! \brief A value that can never be a valid FileHandle.
 const FileHandle kInvalidFileHandle = -1;
 
+using FileOperationResult = ssize_t;
+
 #elif defined(OS_WIN)
 
 using FileHandle = HANDLE;
 using FileOffset = LONGLONG;
 using ScopedFileHandle = ScopedFileHANDLE;
+using FileOperationResult = LONG_PTR;
 
 const FileHandle kInvalidFileHandle = INVALID_HANDLE_VALUE;
 
@@ -126,7 +129,7 @@ enum class FileLocking : bool {
 //! \sa LoggingReadFile
 //! \sa CheckedReadFile
 //! \sa CheckedReadFileAtEOF
-ssize_t ReadFile(FileHandle file, void* buffer, size_t size);
+FileOperationResult ReadFile(FileHandle file, void* buffer, size_t size);
 
 //! \brief Writes to a file, retrying when interrupted or following a short
 //!     write on POSIX.
@@ -141,7 +144,7 @@ ssize_t ReadFile(FileHandle file, void* buffer, size_t size);
 //! \sa ReadFile
 //! \sa LoggingWriteFile
 //! \sa CheckedWriteFile
-ssize_t WriteFile(FileHandle file, const void* buffer, size_t size);
+FileOperationResult WriteFile(FileHandle file, const void* buffer, size_t size);
 
 //! \brief Wraps ReadFile(), ensuring that exactly \a size bytes are read.
 //!

util/file/file_io_posix.cc

@@ -28,7 +28,9 @@ namespace {
 struct ReadTraits {
   using VoidBufferType = void*;
   using CharBufferType = char*;
-  static ssize_t Operate(int fd, CharBufferType buffer, size_t size) {
+  static FileOperationResult Operate(int fd,
+                                     CharBufferType buffer,
+                                     size_t size) {
     return read(fd, buffer, size);
   }
 };
@@ -36,21 +38,24 @@ struct ReadTraits {
 struct WriteTraits {
   using VoidBufferType = const void*;
   using CharBufferType = const char*;
-  static ssize_t Operate(int fd, CharBufferType buffer, size_t size) {
+  static FileOperationResult Operate(int fd,
+                                     CharBufferType buffer,
+                                     size_t size) {
     return write(fd, buffer, size);
   }
 };
 
 template <typename Traits>
-ssize_t ReadOrWrite(int fd,
-                    typename Traits::VoidBufferType buffer,
-                    size_t size) {
+FileOperationResult ReadOrWrite(int fd,
+                                typename Traits::VoidBufferType buffer,
+                                size_t size) {
   typename Traits::CharBufferType buffer_c =
       reinterpret_cast<typename Traits::CharBufferType>(buffer);
 
-  ssize_t total_bytes = 0;
+  FileOperationResult total_bytes = 0;
   while (size > 0) {
-    ssize_t bytes = HANDLE_EINTR(Traits::Operate(fd, buffer_c, size));
+    FileOperationResult bytes =
+        HANDLE_EINTR(Traits::Operate(fd, buffer_c, size));
     if (bytes < 0) {
       return bytes;
     } else if (bytes == 0) {
@@ -102,11 +107,13 @@ FileHandle OpenFileForOutput(int rdwr_or_wronly,
 
 }  // namespace
 
-ssize_t ReadFile(FileHandle file, void* buffer, size_t size) {
+FileOperationResult ReadFile(FileHandle file, void* buffer, size_t size) {
   return ReadOrWrite<ReadTraits>(file, buffer, size);
 }
 
-ssize_t WriteFile(FileHandle file, const void* buffer, size_t size) {
+FileOperationResult WriteFile(FileHandle file,
+                              const void* buffer,
+                              size_t size) {
   return ReadOrWrite<WriteTraits>(file, buffer, size);
 }
 

util/file/file_io_win.cc

@@ -72,7 +72,7 @@ FileHandle OpenFileForOutput(DWORD access,
 
 // TODO(scottmg): Handle > DWORD sized writes if necessary.
 
-ssize_t ReadFile(FileHandle file, void* buffer, size_t size) {
+FileOperationResult ReadFile(FileHandle file, void* buffer, size_t size) {
   DCHECK(!IsSocketHandle(file));
   DWORD size_dword = base::checked_cast<DWORD>(size);
   DWORD total_read = 0;
@@ -103,7 +103,9 @@ ssize_t ReadFile(FileHandle file, void* buffer, size_t size) {
   return total_read;
 }
 
-ssize_t WriteFile(FileHandle file, const void* buffer, size_t size) {
+FileOperationResult WriteFile(FileHandle file,
+                              const void* buffer,
+                              size_t size) {
   // TODO(scottmg): This might need to handle the limit for pipes across a
   // network in the future.
   DWORD size_dword = base::checked_cast<DWORD>(size);