[Bindings] Create and use V8 context snapshots

gin/BUILD.gn

Index: gin/BUILD.gn
diff --git a/gin/BUILD.gn b/gin/BUILD.gn
index e5b6d9ebc5c9d8b4ebc89153df125cc6a2078a87..feb2efb341e6f4704031f3f48dcc0bb86b881b18 100644
--- a/gin/BUILD.gn
+++ b/gin/BUILD.gn
@@ -95,11 +95,11 @@ component("gin") {
   }
 
   defines = [ "GIN_IMPLEMENTATION" ]
-
   public_deps = [
     "//base",
     "//v8",
   ]
+
   deps = [
     ":gin_features",
     "//base/third_party/dynamic_annotations",
@@ -130,6 +130,51 @@ executable("gin_shell") {
   configs += [ "//v8:external_startup_data" ]
 }
 
+action("run_gin_blink_snapshot") {
+  script = "run.py"
+  exec = "$root_out_dir/gin_blink_snapshot"

[Yuki, 2017/04/28 13:48:27]

Not so bad, but a little confusing name, I think.
We don't take a snapshot of Blink...

You can add a header comment for action("run_gin_blink_snapshot") describing
what it does and what it is meant for.

[peria, 2017/06/01 08:33:31]

Done.

+  output_file = "$root_out_dir/context_blob.bin"
+  output_path = rebase_path(output_file, root_build_dir)
+
+  args = [
+    rebase_path(exec, root_build_dir),
+    "--output_file=$output_path",
+  ]
+
+  outputs = [
+    output_file,
+  ]
+
+  deps = [
+    ":gin_blink_snapshot($host_toolchain)",
+  ]
+}
+
+config("noicf") {
+  if (is_win) {
+    ldflags = [ "/OPT:NOICF" ]
+  } else if (is_posix && !is_mac) {
+    ldflags = [ "-Wl,--icf=none" ]
+  }
+}
+
+executable("gin_blink_snapshot") {
+  sources = [
+    "shell/gin_prepare_main.cc",
+  ]
+
+  deps = [
+    ":gin",
+    "//mojo/edk/system:system",
+    "//third_party/WebKit/public:blink",
+  ]
+
+  configs += [
+    "//v8:external_startup_data",
+    ":noicf",

[Yuki, 2017/04/28 13:48:27]

Better to comment why we need :noicf.

[peria, 2017/06/20 10:20:13]

Done.

+  ]
+}
+
 source_set("gin_test") {
   testonly = true
   sources = [