Reland "Set a default got_revision property in the bot_update json output."

This is a reland of commit 05381726

The change was not related to the errors that it was reverted for, so no
changes are necessary.

Original change's description:
> Set a default got_revision property in the bot_update json output.
>
> The bot_update.py script sets a got_revision property by default even if
> it is not present in the reverse revision mapping. This results in an
> uncaught exception when set_output_commit is set to True if got_revision
> isn't present in the reverse revision mapping, but it isn't caught until
> production because the test API doesn't match that behavior. This change
> updates the test API method to match the behavior of the script.
>
> Recipe-Nontrivial-Roll: build
> Recipe-Nontrivial-Roll: build_limited
> Recipe-Nontrivial-Roll: chromiumos
> Recipe-Nontrivial-Roll: infra
> Change-Id: Ideefa9d77d2a816ae66a2bb52737264ed3f5bcee
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3575361
> Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
> Reviewed-by: Josip Sokcevic <sokcevic@google.com>
> Commit-Queue: Garrett Beaty <gbeaty@google.com>
> Auto-Submit: Garrett Beaty <gbeaty@google.com>

Recipe-Nontrivial-Roll: build
Recipe-Nontrivial-Roll: build_limited
Recipe-Nontrivial-Roll: chromiumos
Recipe-Nontrivial-Roll: infra
Change-Id: I80efeee8a2b951df43b00d89bb596dc2cf2fcec7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3582182Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Garrett Beaty <gbeaty@google.com>

recipes/README.recipes.md

@@ -59,7 +59,7 @@ Recipe module to ensure a checkout is consistent on a bot.
 
 Wrapper for easy calling of bot_update.
 
-— **def [deapply\_patch](/recipes/recipe_modules/bot_update/api.py#522)(self, bot_update_step):**
+— **def [deapply\_patch](/recipes/recipe_modules/bot_update/api.py#523)(self, bot_update_step):**
 
 Deapplies a patch, taking care of DEPS and solution revisions properly.
     
@@ -93,7 +93,7 @@ Args:
     bot_update module ONLY supports one change. Users may specify a change
     via tryserver.set_change() and explicitly set this flag False.
 
-— **def [get\_project\_revision\_properties](/recipes/recipe_modules/bot_update/api.py#499)(self, project_name, gclient_config=None):**
+— **def [get\_project\_revision\_properties](/recipes/recipe_modules/bot_update/api.py#500)(self, project_name, gclient_config=None):**
 
 Returns all property names used for storing the checked-out revision of
 a given project.
@@ -109,7 +109,7 @@ Returns (list of str): All properties that'll hold the checked-out revision
 
 &emsp; **@property**<br>&mdash; **def [last\_returned\_properties](/recipes/recipe_modules/bot_update/api.py#49)(self):**
 
-&mdash; **def [resolve\_fixed\_revision](/recipes/recipe_modules/bot_update/api.py#450)(self, bot_update_json, name):**
+&mdash; **def [resolve\_fixed\_revision](/recipes/recipe_modules/bot_update/api.py#451)(self, bot_update_json, name):**
 
 Sets a fixed revision for a single dependency using project revision
 properties.

recipes/recipe_modules/bot_update/api.py

@@ -362,7 +362,8 @@ class BotUpdateApi(recipe_api.RecipeApi):
 
         # Set output commit of the build.
         if (set_output_commit and
-            'got_revision' in self._last_returned_properties):
+            'got_revision' in self._last_returned_properties and
+            'got_revision' in reverse_rev_map):
           # As of April 2019, got_revision describes the output commit,
           # the same commit that Build.output.gitiles_commit describes.
           # In particular, users tend to set got_revision to make Milo display

recipes/recipe_modules/bot_update/examples/full.expected/deprecated_got_revision_mapping.json

@@ -122,7 +122,8 @@
       "@@@STEP_LOG_LINE@json.output@  \"patch_root\": \"src\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"properties\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"got_cr_revision\": \"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_cr_revision_cp\": \"refs/heads/main@{#170242}\"@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"got_cr_revision_cp\": \"refs/heads/main@{#170242}\", @@@",
+      "@@@STEP_LOG_LINE@json.output@    \"got_revision\": \"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\"@@@",
       "@@@STEP_LOG_LINE@json.output@  }, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"root\": \"src\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"source_manifest\": {@@@",
@@ -140,7 +141,8 @@
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@",
       "@@@SET_BUILD_PROPERTY@got_cr_revision@\"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_cr_revision_cp@\"refs/heads/main@{#170242}\"@@@"
+      "@@@SET_BUILD_PROPERTY@got_cr_revision_cp@\"refs/heads/main@{#170242}\"@@@",
+      "@@@SET_BUILD_PROPERTY@got_revision@\"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\"@@@"
     ]
   },
   {
@@ -208,7 +210,8 @@
       "@@@STEP_LOG_LINE@json.output@  \"patch_root\": \"src\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"properties\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"got_cr_revision\": \"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_cr_revision_cp\": \"refs/heads/main@{#170242}\"@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"got_cr_revision_cp\": \"refs/heads/main@{#170242}\", @@@",
+      "@@@STEP_LOG_LINE@json.output@    \"got_revision\": \"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\"@@@",
       "@@@STEP_LOG_LINE@json.output@  }, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"root\": \"src\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"source_manifest\": {@@@",

recipes/recipe_modules/bot_update/test_api.py

@@ -34,6 +34,7 @@ class BotUpdateTestApi(recipe_test_api.RecipeTestApi):
         property_name: revisions[project_name]
         for property_name, project_name in revision_mapping.items()
     }
+    properties.setdefault('got_revision', self.gen_revision(first_sln))
     if commit_positions:
 
       def get_ref(project_name):