Implement serial API for Windows.

base/platform_file_posix.cc

Index: base/platform_file_posix.cc
diff --git a/base/platform_file_posix.cc b/base/platform_file_posix.cc
index 9b42c7a184fea0d22ee060e1e3022c87325686c3..ec0202628e5928d92cda33ff809d75b9e9ce4cb7 100644
--- a/base/platform_file_posix.cc
+++ b/base/platform_file_posix.cc
@@ -78,6 +78,10 @@ PlatformFile CreatePlatformFile(const FilePath& name, int flags,
     NOTREACHED();
   }
 
+  if (flags & PLATFORM_FILE_TERMINAL_DEVICE) {
+    open_flags |= O_NOCTTY | O_NDELAY;
+  }
+
   COMPILE_ASSERT(O_RDONLY == 0, O_RDONLY_must_equal_zero);
 
   int mode = S_IRUSR | S_IWUSR;
@@ -166,6 +170,10 @@ int ReadPlatformFile(PlatformFile file, int64 offset, char* data, int size) {
   do {
     rv = HANDLE_EINTR(pread(file, data + bytes_read,
                             size - bytes_read, offset + bytes_read));
+    if (rv <= 0 && errno == ESPIPE) {
+      // The file descriptor represents a tty device. Try again without lseek.
+      rv = HANDLE_EINTR(read(file, data, size));
+    }
     if (rv <= 0)
       break;
 
@@ -195,6 +203,10 @@ int WritePlatformFile(PlatformFile file, int64 offset,
   do {
     rv = HANDLE_EINTR(pwrite(file, data + bytes_written,
                              size - bytes_written, offset + bytes_written));
+    if (rv <= 0 && errno == ESPIPE) {
+      // The file descriptor represents a tty device. Try again without lseek.
+      rv = HANDLE_EINTR(write(file, data, size));
+    }
     if (rv <= 0)
       break;