gn: Fix more build issues on Win

third_party/protobuf/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 if (is_win) {
   config_h_dir = "vsprojects"
 } else {
   config_h_dir = "."
 }
 
 config("protobuf_config") {
   include_dirs = [
     "src",
     config_h_dir,
   ]
   defines = [
-    "PROTOBUF_USE_DLLS",
     "GOOGLE_PROTOBUF_NO_RTTI",
     "GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER",
   ]
 
   if (is_win) {
     # TODO(jschuh): http://crbug.com/167187 size_t -> int.
     cflags = [ "/wd4267" ]
   }
 }
 
+if (component_mode == "shared_library") {
+  config("protobuf_use_dlls") {
+    defines = [ "PROTOBUF_USE_DLLS" ]
+  }
+}
+
 # This condif should be applied to targets using generated code from the proto
 # compiler. It sets up the include directories properly.
 config("using_proto") {
   include_dirs = [
     "$root_gen_dir/protoc_out",
   ]
 }
 
 protobuf_lite_sources = [
   "src/google/protobuf/extension_set.cc",
@@ skipping 39 matching lines @@
 if (is_win) {
   protobuf_lite_cflags = [
     "/wd4018",  # signed/unsigned mismatch in comparison
     "/wd4244",  # implicit conversion, possible loss of data
     "/wd4355",  # 'this' used in base member initializer list
     "/wd4267",  # size_t to int truncation
     "/wd4291",  # no matching operator delete for a placement new
   ]
 }
 
-source_set("protobuf_lite") {
+component("protobuf_lite") {
   sources = protobuf_lite_sources
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
   if (is_win) {
     configs -= [ "//build/config/win:lean_and_mean" ]
   }
   public_configs = [ ":protobuf_config" ]
 
   cflags = protobuf_lite_cflags
 
   # Required for component builds. See http://crbug.com/172800.
-  defines = [ "LIBPROTOBUF_EXPORTS" ]
+  if (component_mode == "shared_library") {
+    public_configs += [ ":protobuf_use_dlls" ]
+    defines = [ "LIBPROTOBUF_EXPORTS" ]
+  }
 }
 
 # This is the full, heavy protobuf lib that's needed for c++ .protos that don't
 # specify the LITE_RUNTIME option. The protocol compiler itself (protoc) falls
 # into that category. Do not use in Chrome code.
 
 source_set("protobuf_full") {
   # Prevent people from depending on this outside our file.
   visibility = [ ":*" ]
 
@@ skipping 132 matching lines @@
       configs -= [ "//build/config/win:lean_and_mean" ]
     }
 
     cflags = protobuf_lite_cflags
 
     deps = [
       ":protobuf_full",
     ]
   }
 }