Auto-generate restricted trace .gitignore.

I'm going to add a non-ignored subdirectory so it behooves us to fix
our blanket suppression. This will also allow users to clean up stale
trace files.

Bug: angleproject:4090
Bug: b/168049670
Change-Id: I5b0879eb3eebf3b352bb78e3b927203f9483c89f
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2426885
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Cody Northrop <cnorthrop@google.com>

scripts/code_generation_hashes/restricted_traces.json

@@ -1,4 +1,6 @@
 {
+  "src/tests/restricted_traces/.gitignore":
+    "0eb7d74b8842c59d8b4692842bf31209",
   "src/tests/restricted_traces/angry_birds_2_1500.tar.gz.sha1":
     "44fc5437c4a84012e338b3da4b6fc28a",
   "src/tests/restricted_traces/candy_crush_500.tar.gz.sha1":
@@ -8,7 +10,7 @@
   "src/tests/restricted_traces/egypt_1500.tar.gz.sha1":
     "1d80caa37b937f83c95cd053b1bdd4ac",
   "src/tests/restricted_traces/gen_restricted_traces.py":
-    "321e6bb9078501db78299c54980f96ac",
+    "a520ef50175b1b9a20383a884e293b54",
   "src/tests/restricted_traces/manhattan_10.tar.gz.sha1":
     "752781119592a190cc02b773adf38fc3",
   "src/tests/restricted_traces/mobile_legends.tar.gz.sha1":

src/tests/restricted_traces/.gitignore

@@ -1,2 +1,20 @@
-*/
-*.tar.gz
+angry_birds_2_1500.tar.gz
+angry_birds_2_1500/
+candy_crush_500.tar.gz
+candy_crush_500/
+cod_mobile.tar.gz
+cod_mobile/
+egypt_1500.tar.gz
+egypt_1500/
+manhattan_10.tar.gz
+manhattan_10/
+mobile_legends.tar.gz
+mobile_legends/
+nba2k20_800.tar.gz
+nba2k20_800/
+subway_surfer_500.tar.gz
+subway_surfer_500/
+temple_run_300.tar.gz
+temple_run_300/
+trex_200.tar.gz
+trex_200/

src/tests/restricted_traces/gen_restricted_traces.py

@@ -275,6 +275,13 @@ def gen_source(source_file, format_args):
     return True
 
 
+def gen_git_ignore(traces):
+    ignores = ['%s/' % trace for trace in traces] + ['%s.tar.gz' % trace for trace in traces]
+    with open('.gitignore', 'w') as out_file:
+        out_file.write('\n'.join(sorted(ignores)))
+    return True
+
+
 def read_json(json_file):
     with open(json_file) as map_file:
         return json.loads(map_file.read(), object_pairs_hook=reject_duplicate_keys)
@@ -295,7 +302,7 @@ def main():
     # auto_script parameters.
     if len(sys.argv) > 1:
         inputs = [json_file] + [get_sha1_name(trace) for trace in traces]
-        outputs = [gni_file, header_file, source_file]
+        outputs = [gni_file, header_file, source_file, '.gitignore']
 
         if sys.argv[1] == 'inputs':
             print ','.join(inputs)
@@ -339,6 +346,10 @@ def main():
         print('.cpp file generation failed.')
         return 1
 
+    if not gen_git_ignore(traces):
+        print('.gitignore file generation failed')
+        return 1
+
     return 0