Add an action to create a symbol file for the Blimp engine

blimp/BUILD.gn

Index: blimp/BUILD.gn
diff --git a/blimp/BUILD.gn b/blimp/BUILD.gn
index a2241473e0f0908100f3b41abc50a9ef5ce2cdbc..f7191103828b6b8f10dbcb5e758415c398555c9e 100644
--- a/blimp/BUILD.gn
+++ b/blimp/BUILD.gn
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/chrome_build.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
@@ -30,6 +31,10 @@ group("blimp") {
       "//blimp/engine",
       "//blimp/engine:blimp_engine_bundle",
     ]
+
+    if (is_official_build) {
+      deps += [ "//blimp/engine:blimp_symbols" ]
+    }
   }
 
   if (is_linux && !is_chromeos && use_x11) {