[web_engine] Update drone to use flutter mirror

Test: grep -r "external/github.com/flutter/engine" . returns none
Bug: https://github.com/flutter/flutter/issues/99922
Change-Id: I0029903962ddb562f4f10d8d7dafa412983c002a
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/27861
Reviewed-by: Yusuf Mohsinally <mohsinally@google.com>
Commit-Queue: Casey Hillers <chillers@google.com>
diff --git a/recipes/engine/web_engine.expected/linux-post-submit.json b/recipes/engine/web_engine.expected/linux-post-submit.json
index 0eb78ad..a7aa894 100644
--- a/recipes/engine/web_engine.expected/linux-post-submit.json
+++ b/recipes/engine/web_engine.expected/linux-post-submit.json
@@ -849,7 +849,7 @@
     },
     "infra_step": true,
     "name": "buildbucket.schedule",
-    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"builder\": \"Linux Web Drone\"}, \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"priority\": 25, \"properties\": {\"command_args\": [\"test\", \"--browser=chrome\", \"--require-skia-gold\"], \"command_name\": \"chrome-unit-linux\", \"git_ref\": \"refs/heads/master\", \"git_url\": \"https://chromium.googlesource.com/external/github.com/flutter/engine\", \"inherited_dependencies\": [], \"local_engine_cas_hash\": \"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0\", \"web_dependencies\": [\"chrome\"]}, \"requestId\": \"0-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"parent_buildbucket_id\", \"value\": \"0\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}, {\"scheduleBuild\": {\"builder\": {\"builder\": \"Linux Web Drone\"}, \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"priority\": 25, \"properties\": {\"command_args\": [\"test\", \"--browser=firefox\"], \"command_name\": \"firefox-unit-linux\", \"git_ref\": \"refs/heads/master\", \"git_url\": \"https://chromium.googlesource.com/external/github.com/flutter/engine\", \"inherited_dependencies\": [], \"local_engine_cas_hash\": \"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0\", \"web_dependencies\": []}, \"requestId\": \"0-00000000-0000-0000-0000-00000000133a\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"parent_buildbucket_id\", \"value\": \"0\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
+    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"builder\": \"Linux Web Drone\"}, \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"priority\": 25, \"properties\": {\"command_args\": [\"test\", \"--browser=chrome\", \"--require-skia-gold\"], \"command_name\": \"chrome-unit-linux\", \"git_ref\": \"refs/heads/master\", \"git_url\": \"https://flutter.googlesource.com/mirrors/engine\", \"inherited_dependencies\": [], \"local_engine_cas_hash\": \"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0\", \"web_dependencies\": [\"chrome\"]}, \"requestId\": \"0-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"parent_buildbucket_id\", \"value\": \"0\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}, {\"scheduleBuild\": {\"builder\": {\"builder\": \"Linux Web Drone\"}, \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"priority\": 25, \"properties\": {\"command_args\": [\"test\", \"--browser=firefox\"], \"command_name\": \"firefox-unit-linux\", \"git_ref\": \"refs/heads/master\", \"git_url\": \"https://flutter.googlesource.com/mirrors/engine\", \"inherited_dependencies\": [], \"local_engine_cas_hash\": \"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0\", \"web_dependencies\": []}, \"requestId\": \"0-00000000-0000-0000-0000-00000000133a\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"parent_buildbucket_id\", \"value\": \"0\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"responses\": [@@@",
@@ -893,7 +893,7 @@
       "@@@STEP_LOG_LINE@request@          ], @@@",
       "@@@STEP_LOG_LINE@request@          \"command_name\": \"chrome-unit-linux\", @@@",
       "@@@STEP_LOG_LINE@request@          \"git_ref\": \"refs/heads/master\", @@@",
-      "@@@STEP_LOG_LINE@request@          \"git_url\": \"https://chromium.googlesource.com/external/github.com/flutter/engine\", @@@",
+      "@@@STEP_LOG_LINE@request@          \"git_url\": \"https://flutter.googlesource.com/mirrors/engine\", @@@",
       "@@@STEP_LOG_LINE@request@          \"inherited_dependencies\": [], @@@",
       "@@@STEP_LOG_LINE@request@          \"local_engine_cas_hash\": \"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0\", @@@",
       "@@@STEP_LOG_LINE@request@          \"web_dependencies\": [@@@",
@@ -934,7 +934,7 @@
       "@@@STEP_LOG_LINE@request@          ], @@@",
       "@@@STEP_LOG_LINE@request@          \"command_name\": \"firefox-unit-linux\", @@@",
       "@@@STEP_LOG_LINE@request@          \"git_ref\": \"refs/heads/master\", @@@",
-      "@@@STEP_LOG_LINE@request@          \"git_url\": \"https://chromium.googlesource.com/external/github.com/flutter/engine\", @@@",
+      "@@@STEP_LOG_LINE@request@          \"git_url\": \"https://flutter.googlesource.com/mirrors/engine\", @@@",
       "@@@STEP_LOG_LINE@request@          \"inherited_dependencies\": [], @@@",
       "@@@STEP_LOG_LINE@request@          \"local_engine_cas_hash\": \"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0\", @@@",
       "@@@STEP_LOG_LINE@request@          \"web_dependencies\": []@@@",
diff --git a/recipes/engine/web_engine.py b/recipes/engine/web_engine.py
index 7454947..94de584 100644
--- a/recipes/engine/web_engine.py
+++ b/recipes/engine/web_engine.py
@@ -40,9 +40,7 @@
     'recipe_engine/swarming',
 ]
 
-GIT_REPO = (
-    'https://chromium.googlesource.com/external/github.com/flutter/engine'
-)
+GIT_REPO = 'https://flutter.googlesource.com/mirrors/engine'
 
 PROPERTIES = InputProperties
 ENV_PROPERTIES = EnvProperties
diff --git a/recipes/engine/web_engine_drone.expected/linux-error.json b/recipes/engine/web_engine_drone.expected/linux-error.json
index 932f5e7..2158d36 100644
--- a/recipes/engine/web_engine_drone.expected/linux-error.json
+++ b/recipes/engine/web_engine_drone.expected/linux-error.json
@@ -235,7 +235,7 @@
       "The recipe has crashed at point 'Uncaught exception'!",
       "",
       "Traceback (most recent call last):",
-      "  File \"RECIPE_REPO[flutter]/recipes/engine/web_engine_drone.py\", line 84, in RunSteps",
+      "  File \"RECIPE_REPO[flutter]/recipes/engine/web_engine_drone.py\", line 82, in RunSteps",
       "    api.web_util.prepare_web_dependencies(checkout)",
       "  File \"RECIPE_REPO[flutter]/recipe_modules/web_util/api.py\", line 86, in prepare_web_dependencies",
       "    raise ValueError('Web Dependency %s not available.' % dep)",
diff --git a/recipes/engine/web_engine_drone.py b/recipes/engine/web_engine_drone.py
index 7b68f74..9156c0f 100644
--- a/recipes/engine/web_engine_drone.py
+++ b/recipes/engine/web_engine_drone.py
@@ -40,9 +40,7 @@
     'recipe_engine/step',
 ]
 
-GIT_REPO = (
-    'https://chromium.googlesource.com/external/github.com/flutter/engine'
-)
+GIT_REPO = 'https://flutter.googlesource.com/mirrors/engine'
 
 PROPERTIES = InputProperties
 ENV_PROPERTIES = EnvProperties
diff --git a/recipes/infra/ci_yaml.py b/recipes/infra/ci_yaml.py
index 26ed4e8..e4336d6 100644
--- a/recipes/infra/ci_yaml.py
+++ b/recipes/infra/ci_yaml.py
@@ -123,7 +123,7 @@
       'basic',
       api.buildbucket.ci_build(
           bucket='prod',
-          git_repo='https://chromium.googlesource.com/external/github.com/flutter/engine',
+          git_repo='https://flutter.googlesource.com/mirrors/engine',
           revision = 'abc123'
       ),
       api.properties(
@@ -140,7 +140,7 @@
       'release',
       api.buildbucket.ci_build(
           bucket='prod',
-          git_repo='https://chromium.googlesource.com/external/github.com/flutter/engine',
+          git_repo='https://flutter.googlesource.com/mirrors/engine',
           revision = 'abc123'
       ),
       api.properties(
@@ -157,7 +157,7 @@
       'staging',
       api.buildbucket.ci_build(
           bucket='staging',
-          git_repo='https://chromium.googlesource.com/external/github.com/flutter/engine',
+          git_repo='https://flutter.googlesource.com/mirrors/engine',
           revision = 'abc123'
       ),
       api.properties(