Fixup jumbo.gni (-Wno-subobject-linkage)

build/jumbo.gni

 import("//build/split_static_library.gni")  # When someone uses that target_type
 
 declare_args() {
   # If true, use a jumbo build (files compiled together) to speed up
   # compilation.
   use_blink_jumbo_build = true
 
   # A target to exclude from jumbo builds, for optimal round trip time
   # when frequently changing a single cpp file.
   jumbo_build_excluded = ""
@@ skipping 59 matching lines @@
   target(target_type, target_name) {
     deps = []
     if (defined(invoker.deps)) {
       deps += invoker.deps
     }
 
     # Take everything else not handled above from the invoker.
     variables_to_not_forward = [ "deps" ]
     if (use_jumbo_build) {
       deps += [ ":" + target_name + "_jumbo" ]
+
+      if (is_android && !is_clang) {
+        cflags = []
+        if (defined(invoker.cflags)) {
+          cflags += invoker.cflags
+        }
+        cflags += [ "-Wno-subobject-linkage" ]
+        variables_to_not_forward += [ "cflags" ]
+      }
+
       variables_to_not_forward += [ "sources" ]
       assert(jumbo_files != [])
       sources = jumbo_files + excluded_sources
 
       # And the headers so that dependency checks work.
       foreach(source_file, invoker.sources) {
         if (get_path_info(source_file, "extension") == "h") {
           sources += [ source_file ]
         }
       }
+
+      # Can't mix in Objective-C code in a cc file (FIXME).
+      foreach(source_file, invoker.sources) {
+        if (get_path_info(source_file, "extension") == "mm") {
+          sources += [ source_file ]
+        }
+      }
     }
     forward_variables_from(invoker, "*", variables_to_not_forward)
   }
 }
 
 set_defaults("jumbo_target") {
   # This sets the default list of configs when the content_source_set target
   # is defined. The default_compiler_configs comes from BUILDCONFIG.gn and
   # is the list normally applied to static libraries and source sets.
   configs = default_compiler_configs
 }