Fix imports in gcc_toolchain.gni to not rely on //tools.

build/toolchain/gcc_toolchain.gni

Index: build/toolchain/gcc_toolchain.gni
diff --git a/build/toolchain/gcc_toolchain.gni b/build/toolchain/gcc_toolchain.gni
index 2ac3e48b760a92d2a32234866e61d1b837b54da9..efc79b3fc413e2f8fe0c135884e5f4ff43fe6fd4 100644
--- a/build/toolchain/gcc_toolchain.gni
+++ b/build/toolchain/gcc_toolchain.gni
@@ -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/android/config.gni")
 import("//build/config/clang/clang.gni")
 import("//build/config/nacl/config.gni")
 import("//build/config/sanitizers/sanitizers.gni")
@@ -9,7 +10,6 @@ import("//build/config/v8_target_cpu.gni")
 import("//build/toolchain/cc_wrapper.gni")
 import("//build/toolchain/goma.gni")
 import("//build/toolchain/toolchain.gni")
-import("//tools/grit/grit_rule.gni")
 
 # This template defines a toolchain for something that works like gcc
 # (including clang).