Fix optional neon support

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")
 if (cpu_arch == "arm") {
   import("//build/config/arm.gni")
 }
 if (is_posix) {
   import("//build/config/gcc/gcc_version.gni")
@@ skipping 116 matching lines @@
       ldflags += [ "-m64" ]
     } else if (cpu_arch == "x86") {
       cflags += [ "-m32" ]
       ldflags += [ "-m32" ]
     } else if (cpu_arch == "arm") {
       # Don't set the compiler flags for the WebView build. These will come
       # from the Android build system.
       if (!is_android_webview_build) {
         cflags += [
           "-march=$arm_arch",
-          "-mfpu=$arm_fpu",
           "-mfloat-abi=$arm_float_abi",
         ]
         if (arm_tune != "") {
           cflags += [ "-mtune=$arm_tune" ]
         }
         if (arm_use_thumb) {
           cflags += [ "-mthumb" ]
           if (is_android && !is_clang) {  # Clang doesn't support this option.
             cflags += [ "-mthumb-interwork" ]
           }
@@ skipping 159 matching lines @@
         ]
         ldflags += [ "-target arm-linux-androideabi" ]
       } else if (cpu_arch == "x86") {
         cflags += [ "-target x86-linux-androideabi" ]
         ldflags += [ "-target x86-linux-androideabi" ]
       }
     }
   }
 }
 
+config("compiler_arm_fpu") {
+  if (cpu_arch == "arm" && !is_android_webview_build) {
+    cflags = [
+      "-mfpu=$arm_fpu",
+    ]
+  }
+}
+
 # runtime_library -------------------------------------------------------------
 #
 # Sets the runtime library and associated options.
 #
 # How do you determine what should go in here vs. "compiler" above? Consider if
 # a target might choose to use a different runtime library (ignore for a moment
 # if this is possible or reasonable on your system). If such a target would want
 # to change or remove your option, put it in the runtime_library config. If a
 # target wants the option regardless, put it in the compiler config.
 
@@ skipping 556 matching lines @@
   } else {
     cflags = [ "-g1" ]
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }