[Not for land] Remove -Wl,--gc-sections

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 1312 matching lines @@
       # Put data and code in their own sections, so that unused symbols
       # can be removed at link time with --gc-sections.
       "-fdata-sections",
       "-ffunction-sections",
     ]
 
     common_optimize_on_ldflags += [
       # Specifically tell the linker to perform optimizations.
       # See http://lwn.net/Articles/192624/ .
       "-Wl,-O1",
-      "-Wl,--gc-sections",
+      # "-Wl,--gc-sections",
     ]
   }
 }
 
 config("default_stack_frames") {
   if (is_posix && !(is_mac || is_ios)) {
     if (using_sanitizer || enable_profiling || is_debug ||
         current_cpu == "arm64") {
       # Explicitly ask for frame pointers, otherwise:
       # * Stacks may be missing for sanitizer and profiling builds.
@@ skipping 295 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
   }
 }