Revert of Presubmit recipe: commit the patch (patchset #3 id:40001 of https://codereview.chromium.org/2398653002/ )

Reason for revert:
Instead of trying to run the presubmit for try jobs and at every commit, let's do it only for try jobs, which worked fine without this CL.

Original issue's description:
> Presubmit recipe: call presubmit_support.py directly
>
> For some reason, presubmit_support.py can't find PRESUBMIT.py
> unless it has a diff. Calling this script directly allows us
> to specify a fake upstream to force it to find a diff and
> therefore be able to find PRESUBMIT.py.
>
> BUG=skia:5823
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2398653002
>
> Committed: https://skia.googlesource.com/skia/+/c1c7c21fdd2793b2c03b8ffc06461a00c4241a18

TBR=rmistry@google.com,borenet@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=skia:5823

Review-Url: https://codereview.chromium.org/2414133003

infra/bots/recipes/swarm_presubmit.expected/presubmit.json

@@ -119,6 +119,16 @@
     },
     "name": "gclient recurse (git config user.email)"
   },
+  {
+    "cmd": [
+      "git",
+      "checkout",
+      "-b",
+      "tmp_00000000-0000-0000-0000-000000000000"
+    ],
+    "cwd": "[CUSTOM_/_B_WORK]/skia",
+    "name": "create git branch"
+  },
   {
     "cmd": [
       "git",
@@ -129,9 +139,10 @@
   },
   {
     "cmd": [
-      "RECIPE_PACKAGE_REPO[depot_tools]/presubmit_support.py",
+      "git",
-      "--commit",
+      "cl",
-      "--upstream=HEAD^",
+      "presubmit",
+      "--force",
       "-v",
       "-v"
     ],
@@ -141,6 +152,35 @@
     },
     "name": "presubmit"
   },
+  {
+    "cmd": [
+      "git",
+      "reset",
+      "--hard",
+      "origin/master"
+    ],
+    "cwd": "[CUSTOM_/_B_WORK]/skia",
+    "name": "git reset"
+  },
+  {
+    "cmd": [
+      "git",
+      "checkout",
+      "origin/master"
+    ],
+    "cwd": "[CUSTOM_/_B_WORK]/skia",
+    "name": "checkout origin/master"
+  },
+  {
+    "cmd": [
+      "git",
+      "branch",
+      "-D",
+      "tmp_00000000-0000-0000-0000-000000000000"
+    ],
+    "cwd": "[CUSTOM_/_B_WORK]/skia",
+    "name": "delete git branch"
+  },
   {
     "name": "$result",
     "recipe_result": null,

infra/bots/recipes/swarm_presubmit.py

@@ -21,20 +21,33 @@ def RunSteps(api):
   api.vars.setup()
   api.core.checkout_steps()
 
-  api.step('git status',
+  # git-cl wants us to be on a branch.
-           cmd=['git', 'status'],
+  branch = 'tmp_%s' % api.uuid.random()
+  api.step('create git branch',
+           cmd=['git', 'checkout', '-b', branch],
            cwd=api.vars.skia_dir)
+  try:
+    api.step('git status',
+             cmd=['git', 'status'],
+             cwd=api.vars.skia_dir)
+
+    depot_tools_path = api.depot_tools.package_repo_resource()
+    env = {'PATH': api.path.pathsep.join([str(depot_tools_path), '%(PATH)s'])}
+    api.step('presubmit',
+             cmd=['git', 'cl', 'presubmit', '--force', '-v', '-v'],
+             cwd=api.vars.skia_dir,
+             env=env)
+  finally:
+    api.step('git reset',
+             cmd=['git', 'reset', '--hard', 'origin/master'],
+             cwd=api.vars.skia_dir)
+    api.step('checkout origin/master',
+             cmd=['git', 'checkout', 'origin/master'],
+             cwd=api.vars.skia_dir)
+    api.step('delete git branch',
+             cmd=['git', 'branch', '-D', branch],
+             cwd=api.vars.skia_dir)
              
-  depot_tools_path = api.depot_tools.package_repo_resource()
-  script = depot_tools_path.join('presubmit_support.py')
-  env = {'PATH': api.path.pathsep.join([str(depot_tools_path), '%(PATH)s'])}
-  # TODO(borenet): --upstream=HEAD^ is a hack to force presubmit_support to
-  # find a diff. Otherwise, it quits early with:
-  #  "Warning, no PRESUBMIT.py found."
-  api.step('presubmit',
-           cmd=[script, '--commit', '--upstream=HEAD^', '-v', '-v'],
-           cwd=api.vars.skia_dir,
-           env=env)
 
 
 def GenTests(api):