Add the mips_dsp_rev build variable.

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.
 
 # MIPS arch variant.
 if (cpu_arch == "mipsel") {
   declare_args() {
     mips_arch_variant = "r1"

[kjellander_chromium, 2015/02/23 13:22:35]

It would be very useful if you could document something about these different
values as well.

[wtc, 2015/02/23 20:15:51]

Done.

   }
 } else if (cpu_arch == "mips64el") {
   if (is_android) {
     declare_args() {
       mips_arch_variant = "r6"
     }
   } else {
     declare_args() {
       mips_arch_variant = "r2"
     }
   }
 }
+
+if (cpu_arch == "mipsel") {
+  declare_args() {
+    # MIPS DSP ASE revision. Possible values are:

[kjellander_chromium, 2015/02/23 13:22:35]

move there three variables into the already existing declare_args block, at line
8.

[wtc, 2015/02/23 20:15:51]

I intend to dedicate the if-else-if block on lines 5-20 to the mips_arch_variant
build variable because that build variable has different default values in
various cases.

Please let me know if you prefer that I move the other build variable
declarations to that if-else-if block. I am very open-minded about this, so
please feel free to tell me!

[kjellander_chromium, 2015/02/25 21:08:07]

I personally prefer not duplicating code, so I would move this up, but I'll
leave it to you (or another reviewer) to decide.

[wtc, 2015/02/27 05:57:19]

Done. Please let me know if you want me to tweak the results.

+    #   0: unavailable
+    #   1: revision 1
+    #   2: revision 2
+    # Default: 0.

[brettw, 2015/02/23 18:51:36]

You don't have to write the default in the comment. The next line lists the
default so people reading the code will know, and GN will tell you the default
in "gn args --list"

[wtc, 2015/02/23 20:15:51]

Done.

+    mips_dsp_rev = 0
+
+    # MIPS floating-point ABI. Possible values are:
+    #   "hard"
+    #   "soft"
+    mips_float_abi = "hard"
+
+    # MIPS32 floating-point register width. Possible values are:
+    #   "fp32"
+    #   "fp64"
+    #   "fpxx"
+    mips_fpu_mode = "fp32"
+  }
+}