Use the crrev recipe module to fetch commit hashes.

scripts/slave/recipes/bisect_test/example_bisect_results.expected/failed_test.json

Index: scripts/slave/recipes/bisect_test/example_bisect_results.expected/failed_test.json
diff --git a/scripts/slave/recipes/bisect_test/example_bisect_results.expected/failed_test.json b/scripts/slave/recipes/bisect_test/example_bisect_results.expected/failed_test.json
index 6d7ef4282c6c6a2a68dc7fe00279ff5e1b837c99..d20d6d403ea784e7ceddae61e1a9edf811f97e48 100644
--- a/scripts/slave/recipes/bisect_test/example_bisect_results.expected/failed_test.json
+++ b/scripts/slave/recipes/bisect_test/example_bisect_results.expected/failed_test.json
@@ -50,36 +50,46 @@
   },
   {
     "cmd": [
-      "git",
-      "log",
-      "--format=hash:%H",
-      "--grep",
-      "^Cr-Commit-Position: refs/heads/master@{#314017}",
-      "-1",
-      "origin/master"
+      "python",
+      "-u",
+      "RECIPE_MODULE[build::crrev]/resources/crrev_client.py",
+      "get_numbering",
+      "--params-file",
+      "{\"number\": 314017, \"numbering_identifier\": \"refs/heads/master\", \"numbering_type\": \"COMMIT_POSITION\", \"project\": \"chromium\", \"repo\": \"chromium/src\"}",
+      "--attempts",
+      "3"
     ],
-    "cwd": "[TMP_BASE]/bogus_tmp_1",
-    "name": "Resolving reference range.resolving commit_pos 314017",
-    "stdout": "/path/to/tmp/",
+    "cwd": "[SLAVE_BUILD]",
+    "name": "Resolving reference range.crrev get commit hash for refs/heads/master@{#314017}",
+    "stdout": "/path/to/tmp/json",
     "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"git_sha\": \"deadbeef\"@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {
     "cmd": [
-      "git",
-      "log",
-      "--format=hash:%H",
-      "--grep",
-      "^Cr-Commit-Position: refs/heads/master@{#314015}",
-      "-1",
-      "origin/master"
+      "python",
+      "-u",
+      "RECIPE_MODULE[build::crrev]/resources/crrev_client.py",
+      "get_numbering",
+      "--params-file",
+      "{\"number\": 314015, \"numbering_identifier\": \"refs/heads/master\", \"numbering_type\": \"COMMIT_POSITION\", \"project\": \"chromium\", \"repo\": \"chromium/src\"}",
+      "--attempts",
+      "3"
     ],
-    "cwd": "[TMP_BASE]/bogus_tmp_1",
-    "name": "Resolving reference range.resolving commit_pos 314015",
-    "stdout": "/path/to/tmp/",
+    "cwd": "[SLAVE_BUILD]",
+    "name": "Resolving reference range.crrev get commit hash for refs/heads/master@{#314015}",
+    "stdout": "/path/to/tmp/json",
     "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"git_sha\": \"c001c0de\"@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {