Revert of Android: Avoid linking with --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 1228 matching lines @@
       "-fdata-sections",
       "-ffunction-sections",
     ]
 
     # We don't omit frame pointers on arm64 since they are required
     # to correctly unwind stackframes which contain system library
     # function frames (crbug.com/391706).
     if (!using_sanitizer && target_cpu != "arm64") {
       cflags += [ "-fomit-frame-pointer" ]
     }
+
+    # Don't use gc-sections since it can cause links to succeed when they
+    # actually shouldn't. http://crbug.com/159847
+    ldflags = common_optimize_on_ldflags - [ "-Wl,--gc-sections" ]
   } else {
     cflags = [ "-O0" ]
     ldflags = []
   }
 }
 
 # Turns up the optimization level. On Windows, this implies whole program
 # optimization and link-time code generation which is very expensive and should
 # be used sparingly.
 config("optimize_max") {
@@ skipping 137 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
   }
 }