[dart_runner][flutter_runner] Produce snapshot profiles during the build.

Test: build
Change-Id: Ic70575c0a659911593f379451bb5cebd1c5ddc98
diff --git a/runtime/dart_runner/kernel/BUILD.gn b/runtime/dart_runner/kernel/BUILD.gn
index ea29b35..f1eddb5 100644
--- a/runtime/dart_runner/kernel/BUILD.gn
+++ b/runtime/dart_runner/kernel/BUILD.gn
@@ -46,11 +46,14 @@
     isolate_snapshot_data = "$target_gen_dir/isolate_data${product_suffix}.bin"
     isolate_snapshot_instructions =
         "$target_gen_dir/isolate_instructions${product_suffix}.bin"
+    snapshot_profile =
+        "$target_gen_dir/snapshot_profile${product_suffix}.json"
     outputs = [
       vm_snapshot_data,
       vm_snapshot_instructions,
       isolate_snapshot_data,
       isolate_snapshot_instructions,
+      snapshot_profile,
     ]
 
     if (invoker.product) {
@@ -78,6 +81,8 @@
           rebase_path(isolate_snapshot_data, root_build_dir),
       "--isolate_snapshot_instructions=" +
           rebase_path(isolate_snapshot_instructions, root_build_dir),
+      "--write_v8_snapshot_profile_to=" +
+          rebase_path(snapshot_profile, root_build_dir),
     ]
     if (is_debug && !invoker.product) {
       args += [ "--enable_asserts" ]
diff --git a/runtime/flutter_runner/kernel/BUILD.gn b/runtime/flutter_runner/kernel/BUILD.gn
index 3ad723a..f5c48da 100644
--- a/runtime/flutter_runner/kernel/BUILD.gn
+++ b/runtime/flutter_runner/kernel/BUILD.gn
@@ -51,11 +51,14 @@
         "$target_gen_dir/isolate_snapshot${product_suffix}.bin"
     isolate_snapshot_instructions =
         "$target_gen_dir/isolate_snapshot_instructions${product_suffix}.bin"
+    snapshot_profile =
+        "$target_gen_dir/snapshot_profile${product_suffix}.json"
     outputs = [
       vm_snapshot_data,
       vm_snapshot_instructions,
       isolate_snapshot_data,
       isolate_snapshot_instructions,
+      snapshot_profile,
     ]
 
     if (invoker.product) {
@@ -83,6 +86,8 @@
           rebase_path(isolate_snapshot_data, root_build_dir),
       "--isolate_snapshot_instructions=" +
           rebase_path(isolate_snapshot_instructions, root_build_dir),
+      "--write_v8_snapshot_profile_to=" +
+          rebase_path(snapshot_profile, root_build_dir),
     ]
     if (is_debug && !invoker.product) {
       args += [ "--enable_asserts" ]