[gin] Fingerprint the V8 snapshot files on Windows and verify before loading the snapshot.

gin/gin.gyp

Index: gin/gin.gyp
diff --git a/gin/gin.gyp b/gin/gin.gyp
index b38dc850e423e8290ea922200bd462004103783f..e3d856d327896e85ea57009e6741a0be70cc38c6 100644
--- a/gin/gin.gyp
+++ b/gin/gin.gyp
@@ -5,6 +5,7 @@
 {
   'variables': {
     'chromium_code': 1,
+    'gin_gen_path': '<(SHARED_INTERMEDIATE_DIR)/gin/',
   },
   'targets': [
     {
@@ -14,7 +15,6 @@
         '../base/base.gyp:base',
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
         '../v8/tools/gyp/v8.gyp:v8',
-
       ],
       'export_dependent_settings': [
         '../base/base.gyp:base',
@@ -78,6 +78,27 @@
         'wrappable.h',
         'wrapper_info.cc',
       ],
+      'conditions': [
+        ['v8_use_external_startup_data==1', {
+          'dependencies': [
+            'gin_v8_snapshot_fingerprint',
+            '../crypto/crypto.gyp:crypto',
+          ],
+          'sources': [
+            '<(gin_gen_path)/v8_snapshot_fingerprint.cc',
+          ],
+        }],
+      ],
+    },
+    {
+      'target_name': 'gin_v8_snapshot_fingerprint',
+      'type': 'none',
+      'variables': {
+        'snapshot_file': '<(PRODUCT_DIR)/snapshot_blob.bin',
+        'natives_file': '<(PRODUCT_DIR)/natives_blob.bin',
+        'output_file': '<(gin_gen_path)/v8_snapshot_fingerprint.cc',
+      },
+      'includes': [ '../gin/fingerprint/fingerprint_v8_snapshot.gypi' ],
     },
     {
       'target_name': 'gin_shell',