Remove MIPS support

build/config/mips.gni

-# Copyright 2015 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 (current_cpu == "mipsel") {
-  declare_args() {
-    # MIPS arch variant. Possible values are:
-    #   "r1"
-    #   "r2"
-    #   "r6"
-    mips_arch_variant = "r1"
-
-    # MIPS DSP ASE revision. Possible values are:
-    #   0: unavailable
-    #   1: revision 1
-    #   2: revision 2
-    mips_dsp_rev = 0
-
-    # MIPS floating-point ABI. Possible values are:
-    #   "hard": sets the GCC -mhard-float option.
-    #   "soft": sets the GCC -msoft-float option.
-    mips_float_abi = "hard"
-
-    # MIPS32 floating-point register width. Possible values are:
-    #   "fp32": sets the GCC -mfp32 option.
-    #   "fp64": sets the GCC -mfp64 option.
-    #   "fpxx": sets the GCC -mfpxx option.
-    mips_fpu_mode = "fp32"
-  }
-} else if (current_cpu == "mips64el") {
-  # MIPS arch variant. Possible values are:
-  #   "r2"
-  #   "r6"
-  if (is_android) {
-    declare_args() {
-      mips_arch_variant = "r6"
-    }
-  } else {
-    declare_args() {
-      mips_arch_variant = "r2"
-    }
-  }
-}