rebaseline.py: if rebaselining all platforms (not listing them explicitly), allow missing platforms

tools/rebaseline.py

Index: tools/rebaseline.py
===================================================================
--- tools/rebaseline.py	(revision 9505)
+++ tools/rebaseline.py	(working copy)
@@ -88,8 +88,10 @@
         self._configs = configs
         if not subdirs:
             self._subdirs = sorted(SUBDIR_MAPPING.keys())
+            self._missing_json_is_fatal = False
         else:
             self._subdirs = subdirs
+            self._missing_json_is_fatal = True

[epoger, 2013/06/11 16:15:33]

After this change, you still get an exception if the caller specified one or
more subdirs and those could not be found:

$ python tools/rebaseline.py --dry-run --subdirs base-shuttle_ubuntu12_ati5770
base-shuttle-win7-intel-angle
# Getting files to rebaseline from JSON summary URL
http://skia-autogen.googlecode.com/svn/gm-actual/base-shuttle_ubuntu12_ati577...
...
# ... found files_to_rebaseline []
# Getting files to rebaseline from JSON summary URL
http://skia-autogen.googlecode.com/svn/gm-actual/base-shuttle-win7-intel-angl...
...
Traceback (most recent call last):
  File "tools/rebaseline.py", line 305, in <module>
    rebaseliner.RebaselineAll()
  File "tools/rebaseline.py", line 263, in RebaselineAll
    filenames = self._GetFilesToRebaseline(json_url=json_url)
  File "tools/rebaseline.py", line 169, in _GetFilesToRebaseline
    raise ValueError(message)
ValueError: unable to load JSON summary URL
http://skia-autogen.googlecode.com/svn/gm-actual/base-shuttle-win7-intel-angl...

         self._json_base_url = json_base_url
         self._json_filename = json_filename
         self._dry_run = dry_run
@@ -144,6 +146,12 @@
     # rather than a list of TESTS, like this:
     #  ['imageblur', 'xfermodes']
     #
+    # If the JSON actual result summary file cannot be loaded, the behavior
+    # depends on self._missing_json_is_fatal:
+    # - if true: execution will halt with an exception
+    # - if false: we will log an error message but return an empty list so we
+    #   go on to the next platform
+    #
     # params:
     #  json_url: URL pointing to a JSON actual result summary file
     #
@@ -153,7 +161,16 @@
     def _GetFilesToRebaseline(self, json_url):
         print ('# Getting files to rebaseline from JSON summary URL %s ...'
                % json_url)
-        json_contents = self._GetContentsOfUrl(json_url)
+        try:
+            json_contents = self._GetContentsOfUrl(json_url)
+        except urllib2.HTTPError:
+            message = 'unable to load JSON summary URL %s' % json_url
+            if self._missing_json_is_fatal:
+                raise ValueError(message)
+            else:
+                print '# %s' % message
+                return []
+
         json_dict = gm_json.LoadFromString(json_contents)
         actual_results = json_dict[gm_json.JSONKEY_ACTUALRESULTS]