Convert component_mode -> is_component_build for GN

Source/core/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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/ui.gni")
 import("//third_party/WebKit/Source/bindings/bindings.gni")
 import("//third_party/WebKit/Source/bindings/core/v8/generated.gni")
 import("//third_party/WebKit/Source/bindings/modules/modules.gni")
 import("//third_party/WebKit/Source/bindings/modules/v8/generated.gni")
@@ skipping 454 matching lines @@
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     "//build/config/compiler:no_size_t_to_int_warning",
   ]
   include_dirs = [
     "$root_gen_dir/blink",
   ]
 
   cflags = []
   defines = []
 
-  if (is_win && component_mode == "shared_library") {
+  if (is_win && is_component_build) {
     defines += [ "USING_V8_SHARED" ]
   }
 
   if (is_win) {
     cflags += [
       # In generated bindings code: "switch contains default but no case".
       # 4701 and 4702 are disabled because of issues in Bison-generated
       # XPathGrammar.cpp.
       "/wd4065",
       "/wd4701",
@@ skipping 554 matching lines @@
     "$blink_core_output_dir/{{source_name_part}}.h",
   ]
   args = [
     "{{source}}",
     rel_blink_core_gen_dir,
     bison_exe,
   ]
 
   deps = make_core_generated_deps
 }