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

build/sanitizers/sanitizers.gyp

Index: build/sanitizers/sanitizers.gyp
diff --git a/build/sanitizers/sanitizers.gyp b/build/sanitizers/sanitizers.gyp
new file mode 100644
index 0000000000000000000000000000000000000000..91dab8a238a4bf933c04c2cbb224ea6381028469
--- /dev/null
+++ b/build/sanitizers/sanitizers.gyp
@@ -0,0 +1,92 @@
+# 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.
+
+{
+  'targets': [
+    {
+      'target_name': 'sanitizer_options',
+      'type': 'static_library',
+      'toolsets': ['host', 'target'],
+      'variables': {
+         # Every target is going to depend on sanitizer_options, so allow
+         # this one to depend on itself.
+         'prune_self_dependency': 1,
+         # Do not let 'none' targets depend on this one, they don't need to.
+         'link_dependency': 1,
+       },
+      'sources': [
+        'sanitizer_options.cc',
+      ],
+      'include_dirs': [
+        '../..',
+      ],
+      # Some targets may want to opt-out from ASan, TSan and MSan and link
+      # without the corresponding runtime libraries. We drop the libc++
+      # dependency and omit the compiler flags to avoid bringing instrumented
+      # code to those targets.
+      'conditions': [
+        ['use_custom_libcxx==1', {
+          'dependencies!': [
+            '../../buildtools/third_party/libc++/libc++.gyp:libcxx_proxy',
+          ],
+        }],
+        ['tsan==1', {
+          'sources': [
+            'tsan_suppressions.cc',
+          ],
+        }],
+        ['lsan==1', {
+          'sources': [
+            'lsan_suppressions.cc',
+          ],
+        }],
+        ['asan==1', {
+          'sources': [
+            'asan_suppressions.cc',
+          ],
+        }],
+      ],
+      'cflags/': [
+        ['exclude', '-fsanitize='],
+        ['exclude', '-fsanitize-'],
+      ],
+      'direct_dependent_settings': {
+        'ldflags': [
+          '-Wl,-u_sanitizer_options_link_helper',
+        ],
+        'target_conditions': [
+          ['_type=="executable"', {
+            'xcode_settings': {
+              'OTHER_LDFLAGS': [
+                '-Wl,-u,__sanitizer_options_link_helper',
+              ],
+            },
+          }],
+        ],
+      },
+    },
+    {
+      # Copy llvm-symbolizer to the product dir so that LKGR bots can package it.
+      'target_name': 'llvm-symbolizer',
+      'type': 'none',
+      'variables': {
+
+       # Path is relative to this GYP file.
+       'llvm_symbolizer_path':
+           '../../third_party/llvm-build/Release+Asserts/bin/llvm-symbolizer<(EXECUTABLE_SUFFIX)',
+      },
+      'conditions': [
+        ['clang==1', {
+          'copies': [{
+            'destination': '<(PRODUCT_DIR)',
+            'files': [
+              '<(llvm_symbolizer_path)',
+            ],
+          }],
+        }],
+      ],
+    },
+  ],
+}
+