Remove android system expat support.

Clean up the gyp/gn files by removing support for linking to the android
system expat. We don't intend to support this in future and the
android_src variable it depends on will be removed soon.

BUG=409851

Review URL: https://codereview.chromium.org/550113003

Cr-Commit-Position: refs/heads/master@{#293843}

third_party/expat/BUILD.gn

@@ -2,10 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-if (is_android) {
-  import("//build/config/android/config.gni")
-}
-
 if (is_linux) {
   config("expat_config") {
     libs = [ "expat" ]
@@ -14,15 +10,9 @@ if (is_linux) {
   group("expat") {
     direct_dependent_configs = [ ":expat_config" ]
   }
-
-  # TODO(GYP) Android needs direct dependent includes of
-  # <android_src>/external/expat/lib
 } else {
   config("expat_config") {
     include_dirs = [ "files/lib" ]
-    if (is_android) {
-      include_dirs += [ "$android_src/external/expat/lib" ]
-    }
     defines = [ "XML_STATIC" ]
   }
 

third_party/expat/expat.gyp

@@ -34,15 +34,6 @@
               '-lexpat',
             ],
           },
-          'conditions': [
-            ['OS=="android"', {
-              'direct_dependent_settings': {
-                'include_dirs': [
-                  '<(android_src)/external/expat/lib',
-                ],
-              },
-            }],
-          ],
         },
       ],
     }, {  # else: use_system_expat != 1