Address some TODO(GYP)s in the GN build.

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 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/android/config.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/toolchain/cc_wrapper.gni")
 import("//build/toolchain/toolchain.gni")
@@ skipping 27 matching lines @@
   binutils_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
                               root_build_dir)
 
   # Compile in such a way as to make it possible for the profiler to unwind full
   # stack frames. Setting this flag has a large effect on the performance of the
   # generated code than just setting profiling, but gives the profiler more
   # information to analyze.
   # Requires profiling to be set to true.
   enable_full_stack_frames_for_profiling = false
 
-  # TODO(GYP): We should be using 64-bit gold for linking on both 64-bit Linux
+  # TODO: We should be using 64-bit gold for linking on both 64-bit Linux
   # and 32-bit linux; 32-bit Gold runs out of address-space on 32-bit builds.
   # However, something isn't quite working right on the 32-bit builds.
   use_gold =
       is_linux && (current_cpu == "x64" || current_cpu == "arm") && !use_lld
 
   # When we are going to use gold we need to find it.
   # This is initialized below, after use_gold might have been overridden.
   gold_path = false
 
   # use_debug_fission: whether to use split DWARF debug info
@@ skipping 1269 matching lines @@
     configs = [ "//build/config/nacl:irt_optimize" ]
   } else {
     ldflags = common_optimize_on_ldflags
     if (is_win) {
       # Favor speed over size, /O2 must be before the common flags. The GYP
       # build also specifies /Ot, /Oi, and /GF, but these are implied by /O2.
       cflags = [ "/O2" ] + common_optimize_on_cflags
 
       # TODO(thakis): Remove is_clang here, https://crbug.com/598772
       if (is_official_build && !is_clang) {
-        # TODO(GYP): TODO(dpranke): Should these only be on in an official

[brettw, 2016/05/04 19:51:28]

I think we should do WPO only in official.

-        # build, or on all the time? For now we'll require official build so
-        # that the compile is clean.
         cflags += [
           "/GL",  # Whole program optimization.
 
           # Disable Warning 4702 ("Unreachable code") for the WPO/PGO builds.
           # Probably anything that this would catch that wouldn't be caught in a
           # normal build isn't going to actually be a bug, so the incremental
           # value of C4702 for PGO builds is likely very small.
           "/wd4702",
         ]
       }
@@ skipping 105 matching lines @@
 
 if (is_ios || is_mac) {
   # On Mac and iOS, this enables support for ARC (automatic ref-counting).
   # See http://clang.llvm.org/docs/AutomaticReferenceCounting.html.
   config("enable_arc") {
     common_flags = [ "-fobjc-arc" ]
     cflags_objc = common_flags
     cflags_objcc = common_flags
   }
 }