[release] Replace raw DEPS processing with gclient getdep

No-Try: true
Bug: chromium:1106435
Change-Id: I120d3930e4e8be7010d8d1f1928829ca0882638d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2304578Reviewed-by: Tamer Tas <tmrts@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68913}

tools/release/auto_roll.py

@@ -46,14 +46,10 @@ class DetectLastRoll(Step):
     self['json_output']['monitoring_state'] = 'detect_last_roll'
     self["last_roll"] = self._options.last_roll
     if not self["last_roll"]:
-      # Interpret the DEPS file to retrieve the v8 revision.
-      # TODO(machenbach): This should be part or the setdep api of
-      # depot_tools.
-      Var = lambda var: '%s'
-      exec(FileToText(os.path.join(self._options.chromium, "DEPS")))
-
-      # The revision rolled last.
-      self["last_roll"] = vars['v8_revision']
+      # Get last-rolled v8 revision from Chromium's DEPS file.
+      self["last_roll"] = self.Command(
+          "gclient", "getdep -r src/v8", cwd=self._options.chromium).strip()
+
     self["last_version"] = self.GetVersionTag(self["last_roll"])
     assert self["last_version"], "The last rolled v8 revision is not tagged."
 

tools/release/test_scripts.py

@@ -558,9 +558,11 @@ deps = {
     TEST_CONFIG["CHROMIUM"] = self.MakeEmptyTempDirectory()
     json_output_file = os.path.join(TEST_CONFIG["CHROMIUM"], "out.json")
     TextToFile(self.FAKE_DEPS, os.path.join(TEST_CONFIG["CHROMIUM"], "DEPS"))
+    chrome_dir = TEST_CONFIG["CHROMIUM"]
     self.Expect([
       Cmd("git fetch origin", ""),
       Cmd("git fetch origin +refs/tags/*:refs/tags/*", ""),
+      Cmd("gclient getdep -r src/v8", "last_roll_hsh", cwd=chrome_dir),
       Cmd("git describe --tags last_roll_hsh", "3.22.4"),
       Cmd("git fetch origin +refs/tags/*:refs/tags/*", ""),
       Cmd("git rev-list --max-age=395200 --tags",
@@ -597,6 +599,7 @@ deps = {
     expectations = [
       Cmd("git fetch origin", ""),
       Cmd("git fetch origin +refs/tags/*:refs/tags/*", ""),
+      Cmd("gclient getdep -r src/v8", "last_roll_hsh", cwd=chrome_dir),
       Cmd("git describe --tags last_roll_hsh", "3.22.3.1"),
       Cmd("git fetch origin +refs/tags/*:refs/tags/*", ""),
       Cmd("git rev-list --max-age=395200 --tags",