Remove natives_blob.bin's arch dependence in Android.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 74a41e587988be9c48f69a3be3f16377a3ed6598..34031d370fe8cd5ef96be1f55ed4c103051535ec 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -515,8 +515,16 @@ if (is_android) {
       deps = [
         "//v8",
       ]
-      renaming_sources = v8_external_startup_data_renaming_sources
-      renaming_destinations = v8_external_startup_data_renaming_destinations
+      sources = [
+        "$root_out_dir/natives_blob.bin",
+      ]
+      renaming_sources = [ "$root_out_dir/snapshot_blob.bin" ]
+      if (current_cpu == "arm" || current_cpu == "x86" ||
+          current_cpu == "mipsel") {
+        renaming_destinations = [ "snapshot_blob_32.bin" ]

[Yang, 2016/06/22 12:59:50]

Does this actually work? in src/startup-data-util.cc we hard-code the default
snapshot file names.

[michaelbai, 2016/06/22 16:00:37]

This target "v8_external_startup_data_assets" isn't used by v8 itself.

The way to load snapshot in startup-data-util.cc doesn't work in Android,
Android loads the snapshot from APK in gin/v8_initializer.cc.

+      } else {
+        renaming_destinations = [ "snapshot_blob_64.bin" ]
+      }
       disable_compression = true
     }
   }