win: Only retry in UseHandler() loop on ERROR_PIPE_BUSY

snapshot/win/end_to_end_test.py

Index: snapshot/win/end_to_end_test.py
diff --git a/snapshot/win/end_to_end_test.py b/snapshot/win/end_to_end_test.py
index 3bbcdb98c6a4699a0941cdc9096f8d73a4395566..ddf48ef2bb4cc0ed461e9bfd812eab6c361cfeee 100644
--- a/snapshot/win/end_to_end_test.py
+++ b/snapshot/win/end_to_end_test.py
@@ -21,6 +21,7 @@ import re
 import subprocess
 import sys
 import tempfile
+import time
 
 g_temp_dirs = []
 
@@ -101,6 +102,14 @@ def GetDumpFromProgram(out_dir, pipe_name, executable_name):
           '--database=' + test_database
       ])
 
+      # Wait until the server is ready.
+      printed = False
+      while not os.path.exists(pipe_name):
+        if not printed:
+          print 'Waiting for crashpad_handler to be ready...'
+          printed = True
+        time.sleep(0.1)
+
       subprocess.call([os.path.join(out_dir, executable_name), pipe_name])
     else:
       subprocess.call([os.path.join(out_dir, executable_name),