Fix rebaseline-o-matic logging

readline blocks, so reading stdout, then stderr doesn't make any
sense because we'll block on each on. So if we print only to one
of them, we'll just wait until the process completes.

Also, simplify the readline loop in RebaselineOMatic to just
use readline instead of poll. That way it avoids missing any
output between the last poll and when the process finishes.

Review URL: https://codereview.chromium.org/329873005

git-svn-id: svn://svn.chromium.org/blink/trunk@176146 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline.py

@@ -762,22 +762,19 @@ class AutoRebaseline(AbstractParallelRebaselineCommand):
         if options.verbose:
             subprocess_command.append('--verbose')
 
-        process = self._tool.executive.popen(subprocess_command, stdout=self._tool.executive.PIPE, stderr=self._tool.executive.PIPE)
+        process = self._tool.executive.popen(subprocess_command, stdout=self._tool.executive.PIPE, stderr=self._tool.executive.STDOUT)
         last_output_time = time.time()
 
         # git cl sometimes completely hangs. Bail if we haven't gotten any output to stdout/stderr in a while.
         while process.poll() == None and time.time() < last_output_time + self.SECONDS_BEFORE_GIVING_UP:
-            # FIXME: This isn't awesome. It may improperly interleave stdout and stderr?
+            # FIXME: This doesn't make any sense. readline blocks, so all this code to
+            # try and bail is useless. Instead, we should do the readline calls on a
+            # subthread. Then the rest of this code would make sense.
             out = process.stdout.readline().rstrip('\n')
             if out:
                 last_output_time = time.time()
                 _log.info(out)
 
-            err = process.stdout.readline().rstrip('\n')
-            if err:
-                last_output_time = time.time()
-                _log.error(err)
-
         if process.poll() == None:
             _log.error('Command hung: %s' % subprocess_command)
             return False
@@ -885,20 +882,13 @@ class RebaselineOMatic(AbstractDeclarativeCommand):
             self._log_to_server(out)
         return out
 
-    def _log_remaining_lines(self, handle):
-        out = self._log_line(handle)
-        while out:
-            out = self._log_line(handle)
-
     def _run_logged_command(self, command):
-        process = self._tool.executive.popen(command, stdout=self._tool.executive.PIPE, stderr=self._tool.executive.PIPE)
-        while process.poll() == None:
-            # FIXME: This should probably batch up lines if they're available and log to the server once.
-            self._log_line(process.stdout)
-            self._log_line(process.stderr)
+        process = self._tool.executive.popen(command, stdout=self._tool.executive.PIPE, stderr=self._tool.executive.STDOUT)
 
-        self._log_remaining_lines(process.stdout)
-        self._log_remaining_lines(process.stderr)
+        out = self._log_line(process.stdout)
+        while out:
+            # FIXME: This should probably batch up lines if they're available and log to the server once.
+            out = self._log_line(process.stdout)
 
     def _do_one_rebaseline(self):
         try: