mojo::RawChannelWin: Use GetOverlappedResult() to retrive read bytes.

The MSDN document suggests that with overlapped I/O, |lpNumberOfBytesRead|
parameter of ReadFile() API isn't reliable and shouldn't be used.
GetOverlappedResult() should be used instead, according to the doc.
See: http://msdn.microsoft.com/en-us/library/windows/desktop/aa365467(v=vs.85).aspx

This is a speculative crash fix for crbug.com/41509. The crash happens
only on Windows. The report also implies that there might be some
message duplication.It is possible if the value of |lpNumberOfBytesRead|
is wrong.

BUG=415059
R=viettrungluu@chromium.org

Review URL: https://codereview.chromium.org/616043003

Cr-Commit-Position: refs/heads/master@{#297500}

1 files changed, 8 insertions, 3 deletions

diff --git a/mojo/system/raw_channel_win.cc b/mojo/system/raw_channel_win.cc
index 1090038..72cec16 100644
--- a/mojo/system/raw_channel_win.cc
+++ b/mojo/system/raw_channel_win.cc
@@ -371,14 +371,12 @@ RawChannel::IOResult RawChannelWin::Read(size_t* bytes_read) {
   size_t bytes_to_read = 0;
   read_buffer()->GetBuffer(&buffer, &bytes_to_read);
 
-  DWORD bytes_read_dword = 0;
   BOOL result = ReadFile(io_handler_->handle(),
                          buffer,
                          static_cast<DWORD>(bytes_to_read),
-                         &bytes_read_dword,
+                         nullptr,
                          &io_handler_->read_context()->overlapped);
   if (!result) {
-    DCHECK_EQ(bytes_read_dword, 0u);
     DWORD error = GetLastError();
     if (error == ERROR_BROKEN_PIPE)
       return IO_FAILED_SHUTDOWN;
@@ -389,6 +387,13 @@ RawChannel::IOResult RawChannelWin::Read(size_t* bytes_read) {
   }
 
   if (result && skip_completion_port_on_success_) {
+    DWORD bytes_read_dword = 0;
+    BOOL get_size_result =
+        GetOverlappedResult(io_handler_->handle(),
+                            &io_handler_->read_context()->overlapped,
+                            &bytes_read_dword,
+                            FALSE);
+    DPCHECK(get_size_result);
     *bytes_read = bytes_read_dword;
     return IO_SUCCEEDED;
   }