Add more debugging to figure out why SharedMemory creation in the browser process might fail.

base/memory/shared_memory_win.cc

Index: base/memory/shared_memory_win.cc
diff --git a/base/memory/shared_memory_win.cc b/base/memory/shared_memory_win.cc
index 6623e8caefde4b74157be1723414706418374f0f..c4b426f5c4979ef30fab42f87a5b4c62ba601f03 100644
--- a/base/memory/shared_memory_win.cc
+++ b/base/memory/shared_memory_win.cc
@@ -377,6 +377,10 @@ bool SharedMemory::ShareToProcessCommon(ProcessHandle process,
 
   if (!::DuplicateHandle(GetCurrentProcess(), mapped_file, process, &result,
                          access, FALSE, options)) {
+    // Debugging to help track down https://crbug.com/585013
+    DWORD last_error = ::GetLastError();
+    base::debug::Alias(&last_error);
+    base::debug::DumpWithoutCrashing();
     return false;
   }
   *new_handle = SharedMemoryHandle(result, base::GetProcId(process));