Reland licenses cpp switch (flutter#172671)

changes since last land:
1) Now the license checker can trim matched licenses to remove regions
that aren't apropos
1) There is a `.autoroller-preupload.sh` script that should update the
LICENSE file when the autoroller executes

relies on:
- flutter#172655
- https://skia-review.googlesource.com/c/buildbot/+/1025936

## Pre-launch Checklist

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responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

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Author: gaaclarke

.autoroller-preupload.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+# Copyright 2014 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# This is executed by the skia autoroller after the roll has happened but before
+# the PR is uploaded. Previously this logic was hardcoded into the autoroller
+# and was reserved for updating the LICENSE file. Now the autoroller delegates
+# to this script.
+# See also:
+#   - https://skia-review.googlesource.com/c/buildbot/+/1025936
+#   - https://issues.skia.org/issues/433551375
+
+REPO_PATH=$(dirname "$(readlink -f "$0")")
+ET="$REPO_PATH/engine/src/flutter/bin/et"
+LICENSE_CPP="$REPO_PATH/engine/src/out/host_profile/licenses_cpp"
+WORKING_DIR="$REPO_PATH/engine/src/flutter"
+LICENSES_PATH="$REPO_PATH/engine/src/flutter/sky/packages/sky_engine/LICENSE"
+DATA_PATH="$REPO_PATH/engine/src/flutter/tools/licenses_cpp/data"
+
+$ET build --no-rbe -c host_profile //flutter/tools/licenses_cpp
+$LICENSE_CPP \
+  --working_dir=$WORKING_DIR \
+  --licenses_path=$LICENSES_PATH \
+  --data_dir=$DATA_PATH \
+  --v=1

dev/bots/analyze.dart

@@ -2653,6 +2653,7 @@ Future<CommandResult> _runFlutterAnalyze(
 
 // These files legitimately require executable permissions
 const Set<String> kExecutableAllowlist = <String>{
+  '.autoroller-preupload.sh',
   'bin/dart',
   'bin/flutter',
   'bin/flutter-dev',

engine/src/flutter/ci/builders/standalone/linux_license.json

@@ -6,11 +6,32 @@
     "cas_archive": false,
     "name": "licenses",
     "description": "Runs the license check script.",
+    "gn": [
+        "--target-dir",
+        "ci/host_release_licenses",
+        "--runtime-mode",
+        "release",
+        "--no-rbe",
+        "--no-goma"
+    ],
+    "ninja": {
+        "config": "ci/host_release_licenses",
+        "targets": [
+            "flutter/tools/licenses_cpp",
+            "flutter/tools/licenses_cpp:licenses_cpp_testrunner"
+        ]
+    },
     "tests": [
         {
-            "name": "licenses check",
-            "max_attempts": 1,
-            "script": "flutter/ci/licenses.sh"
+            "name": "Run license_cpp unittests",
+            "script": "out/ci/host_release_licenses/licenses_cpp_testrunner"
+        },
+        {
+            "name": "Run license_cpp",
+            "script": "flutter/ci/licenses_cpp.sh",
+            "parameters": [
+                "ci/host_release_licenses"
+            ]
         }
     ]
 }

engine/src/flutter/ci/licenses_cpp.sh

@@ -64,7 +64,7 @@ DATA_DIR="$SCRIPT_DIR/../tools/licenses_cpp/data"
 # in the directory where you *run* the script from (your current working directory).
 LICENSES_OUTPUT_PATH="$SCRIPT_DIR/../sky/packages/sky_engine/LICENSE_CPP.new"
 
-LICENSES_PATH="$SCRIPT_DIR/../sky/packages/sky_engine/LICENSE_CPP"
+LICENSES_PATH="$SCRIPT_DIR/../sky/packages/sky_engine/LICENSE"
 
 # --- Validation ---