Do not fail perf upload when try commit cannot be found

This may happen if the gerrit CL correspondingto a try commit is deleted.

Change-Id: Icbb363aed9114f5cf06ffc730c9bdfbfb8e61441
diff --git a/tools/historic_run.py b/tools/historic_run.py
index 9de2e91..81b9b52 100755
--- a/tools/historic_run.py
+++ b/tools/historic_run.py
@@ -130,8 +130,11 @@
     try:
         commit_timestamp_raw = subprocess.check_output(commit_timestamp_cmd)
     except subprocess.CalledProcessError as e:
-        # Try to fetch the hash. This may be needed for try commits.
-        subprocess.check_output(['git', 'fetch', 'origin', hash])
+        try:
+            # Try to fetch the hash. This may be needed for try commits.
+            subprocess.check_output(['git', 'fetch', 'origin', hash])
+        except subprocess.CalledProcessError as e:
+            return None
         commit_timestamp_raw = subprocess.check_output(commit_timestamp_cmd)
     commit_timestamp_str = commit_timestamp_raw.decode('utf-8').strip().splitlines()[-1]
     commit_timestamp = int(commit_timestamp_str)
diff --git a/tools/upload_benchmark_data_to_google_storage.py b/tools/upload_benchmark_data_to_google_storage.py
index e975049..67d984e 100755
--- a/tools/upload_benchmark_data_to_google_storage.py
+++ b/tools/upload_benchmark_data_to_google_storage.py
@@ -117,7 +117,8 @@
         try_hash = key.split('/')[3]
         if try_hash not in seen_try_hashes:
             try_commit = historic_run.git_commit_from_hash(try_hash)
-            try_commits.append(try_commit)
+            if try_commit is not None:
+                try_commits.append(try_commit)
             seen_try_hashes.add(try_hash)
     return try_commits