Add a snapshot of flutter/engine/src/build to our sdk

build/host_jar.gypi

+# Copyright 2014 The Chromium 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 file is meant to be included into a target to provide a rule to build
+# a JAR file for use on a host in a consistent manner. If a main class is
+# specified, this file will also generate an executable to run the jar in the
+# output folder's /bin/ directory.
+#
+# To use this, create a gyp target with the following form:
+# {
+#   'target_name': 'my_jar',
+#   'type': 'none',
+#   'variables': {
+#     'src_paths': [
+#       'path/to/directory',
+#       'path/to/other/directory',
+#       'path/to/individual_file.java',
+#       ...
+#     ],
+#   },
+#   'includes': [ 'path/to/this/gypi/file' ],
+# }
+#
+# Required variables:
+#   src_paths - A list of all paths containing java files that should be
+#     included in the jar. Paths can be either directories or files.
+# Optional/automatic variables:
+#   excluded_src_paths - A list of all paths that should be excluded from
+#     the jar.
+#   generated_src_dirs - Directories containing additional .java files
+#     generated at build time.
+#   input_jars_paths - A list of paths to the jars that should be included
+#     in the classpath.
+#   main_class - The class containing the main() function that should be called
+#     when running the jar file.
+#   jar_excluded_classes - A list of .class files that should be excluded
+#     from the jar.
+
+{
+  'dependencies': [
+    '<(DEPTH)/build/android/setup.gyp:build_output_dirs',
+  ],
+  'variables': {
+    'classes_dir': '<(intermediate_dir)/classes',
+    'excluded_src_paths': [],
+    'generated_src_dirs': [],
+    'input_jars_paths': [],
+    'intermediate_dir': '<(SHARED_INTERMEDIATE_DIR)/<(_target_name)',
+    'jar_dir': '<(PRODUCT_DIR)/lib.java',
+    'jar_excluded_classes': [],
+    'jar_name': '<(_target_name).jar',
+    'jar_path': '<(jar_dir)/<(jar_name)',
+    'main_class%': '',
+    'stamp': '<(intermediate_dir)/jar.stamp',
+    'enable_errorprone%': '0',
+    'errorprone_exe_path': '<(PRODUCT_DIR)/bin.java/chromium_errorprone',
+  },
+  'all_dependent_settings': {
+    'variables': {
+      'input_jars_paths': ['<(jar_path)']
+    },
+  },
+  'actions': [
+    {
+      'action_name': 'javac_<(_target_name)',
+      'message': 'Compiling <(_target_name) java sources',
+      'variables': {
+        'extra_args': [],
+        'extra_inputs': [],
+        'java_sources': [ '<!@(find <@(src_paths) -name "*.java")' ],
+        'conditions': [
+          ['"<(excluded_src_paths)" != ""', {
+            'java_sources!': ['<!@(find <@(excluded_src_paths) -name "*.java")']
+          }],
+          ['"<(jar_excluded_classes)" != ""', {
+            'extra_args': ['--jar-excluded-classes=<(jar_excluded_classes)']
+          }],
+          ['main_class != ""', {
+            'extra_args': ['--main-class=>(main_class)']
+          }],
+          ['enable_errorprone == 1', {
+            'extra_inputs': [
+              '<(errorprone_exe_path)',
+            ],
+            'extra_args': [ '--use-errorprone-path=<(errorprone_exe_path)' ],
+          }],
+        ],
+      },
+      'inputs': [
+        '<(DEPTH)/build/android/gyp/util/build_utils.py',
+        '<(DEPTH)/build/android/gyp/javac.py',
+        '^@(java_sources)',
+        '>@(input_jars_paths)',
+        '<@(extra_inputs)',
+      ],
+      'outputs': [
+        '<(jar_path)',
+        '<(stamp)',
+      ],
+      'action': [
+        'python', '<(DEPTH)/build/android/gyp/javac.py',
+        '--classpath=>(input_jars_paths)',
+        '--src-gendirs=>(generated_src_dirs)',
+        '--chromium-code=<(chromium_code)',
+        '--stamp=<(stamp)',
+        '--jar-path=<(jar_path)',
+        '<@(extra_args)',
+        '^@(java_sources)',
+      ],
+    },
+  ],
+  'conditions': [
+    ['main_class != ""', {
+      'actions': [
+        {
+          'action_name': 'create_java_binary_script_<(_target_name)',
+          'message': 'Creating java binary script <(_target_name)',
+          'variables': {
+            'output': '<(PRODUCT_DIR)/bin/<(_target_name)',
+          },
+          'inputs': [
+            '<(DEPTH)/build/android/gyp/create_java_binary_script.py',
+            '<(jar_path)',
+          ],
+          'outputs': [
+            '<(output)',
+          ],
+          'action': [
+            'python', '<(DEPTH)/build/android/gyp/create_java_binary_script.py',
+            '--classpath=>(input_jars_paths)',
+            '--jar-path=<(jar_path)',
+            '--output=<(output)',
+            '--main-class=>(main_class)',
+          ]
+        }
+      ]
+    }],
+    ['enable_errorprone == 1', {
+      'dependencies': [
+        '<(DEPTH)/third_party/errorprone/errorprone.gyp:chromium_errorprone',
+      ],
+    }],
+  ]
+}
+