Remove an unnecessary NDK include path.

The NDK include path is implied by the --sysroot flag, which we're
already passing everywhere.

Change-Id: I1fefe343e680e899723e05fcd22c2229d8a06f38
Reviewed-on: https://chromium-review.googlesource.com/1103585
Commit-Queue: Peter Collingbourne <pcc@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567884}

build/config/android/config.gni

@@ -266,10 +266,6 @@ if (is_android || is_chromeos) {
 
   android_sdk =
       "${android_sdk_root}/platforms/android-${android_sdk_platform_version}"
-
-  # Path to the Android NDK and SDK.
-  android_ndk_include_dir = "$android_ndk_root/usr/include"
-
   android_sdk_tools = "${android_sdk_root}/tools"
   android_sdk_build_tools =
       "${android_sdk_root}/build-tools/$android_sdk_build_tools_version"

chrome/BUILD.gn

@@ -1784,8 +1784,6 @@ if (is_android) {
       "app/chrome_main_delegate.h",
     ]
 
-    include_dirs = [ android_ndk_include_dir ]
-
     libs = [
       "android",
       "jnigraphics",