Revert of Add a GN flag for the Windows multi-dll build. (patchset #3 id:40001 of https://codereview.chromium.org/1120803003/)

Reason for revert:
May have caused some link errors on windows: https://build.chromium.org/p/chromium.win/builders/Win%20x64%20GN/builds/814

Original issue's description:
> Add a GN flag for the Windows multi-dll build.
>
> The first pass of moving the other Chrome-specific build flags out of the root build config file and into the new one. This requires both ffmpeg and Blink changes to finish landing.
>
> R=scottmg@chromium.org
> TBR=ddorwin@chromium.org (widevine)
>
> Committed: https://crrev.com/edff53a35780ba2f515c7e8d4f7131c91151e1a3
> Cr-Commit-Position: refs/heads/master@{#327854}

TBR=scottmg@chromium.org,brettw@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1117063004

Cr-Original-Commit-Position: refs/heads/master@{#327861}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: e203954b33d80072a7c8d256ffdc69fa42262765

config/BUILD.gn

@@ -3,7 +3,6 @@
 # found in the LICENSE file.
 
 import("//build/config/allocator.gni")
-import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")

config/BUILDCONFIG.gn

@@ -66,13 +66,11 @@ declare_args() {
   # Selects the desired build flavor. Official builds get additional
   # processing to prepare for release. Normally you will want to develop and
   # test with this flag off.
-  # TODO(brettw) move to chrome_build.gni when DEPS are updated.
   is_official_build = false
 
   # Select the desired branding flavor. False means normal Chromium branding,
   # true means official Google Chrome branding (requires extra Google-internal
   # resources).
-  # TODO(brettw) move to chrome_build.gni when DEPS are updated.
   is_chrome_branded = false
 
   # Compile for Address Sanitizer to find memory bugs.

config/chrome_build.gni

@@ -1,21 +0,0 @@
-# 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.
-
-declare_args() {
-  # Selects the desired build flavor. Official builds get additional
-  # processing to prepare for release. Normally you will want to develop and
-  # test with this flag off.
-  # TODO(brettw) move here from BUILDCONFIG.gn when DEPS are updated.
-  #is_official_build = false
-
-  # Select the desired branding flavor. False means normal Chromium branding,
-  # true means official Google Chrome branding (requires extra Google-internal
-  # resources).
-  # TODO(brettw) move here from BUILDCONFIG.gn when DEPS are updated.
-  #is_chrome_branded = false
-
-  # Break chrome.dll into multple pieces based on process type. Only available
-  # on Windows.
-  is_multi_dll_chrome = is_win && !is_component_build
-}

config/compiler/BUILD.gn

@@ -3,7 +3,6 @@
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
-import("//build/config/chrome_build.gni")
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }

config/features.gni

@@ -11,7 +11,6 @@
 #
 # See also build/config/ui.gni
 
-import("//build/config/chrome_build.gni")
 if (is_android) {
   import("//build/config/android/config.gni")
 }

config/mac/mac_sdk.gni

@@ -2,8 +2,6 @@
 # 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")
-
 declare_args() {
   # Minimum supported version of the Mac SDK.
   mac_sdk_min = "10.6"

config/sysroot.gni

@@ -5,8 +5,6 @@
 # This header file defines the "sysroot" variable which is the absolute path
 # of the sysroot. If no sysroot applies, the variable will be an empty string.
 
-import("//build/config/chrome_build.gni")
-
 declare_args() {
   # The absolute path of the sysroot that is applied when compiling using
   # the target toolchain.

secondary/tools/grit/grit_rule.gni

@@ -75,7 +75,6 @@
 #     # You can also put deps here if the grit source depends on generated
 #     # files.
 #   }
-import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")