Rebaseline Android Xoom and Nexus10

Review URL: https://codereview.chromium.org/26257002

git-svn-id: http://skia.googlecode.com/svn/trunk@11627 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tools/svndiff.py b/tools/svndiff.py
index 9e51eee..1821d22 100755
--- a/tools/svndiff.py
+++ b/tools/svndiff.py
@@ -147,10 +147,13 @@
                 imagename=imagename,
                 hash_type=gm_json.JSONKEY_HASHTYPE_BITMAP_64BITMD5,
                 hash_digest=old_checksum)
-            _DownloadUrlToFile(
-                source_url=old_image_url,
-                dest_path=os.path.join(old_flattened_dir,
-                                       filename_prefix + imagename))
+            try:
+                _DownloadUrlToFile(
+                    source_url=old_image_url,
+                    dest_path=os.path.join(old_flattened_dir,
+                                           filename_prefix + imagename))
+            except:
+                print "unable to find image ",  os.path.join(old_flattened_dir, filename_prefix + imagename)
 
         new_checksum = results['new']
         if new_checksum: