diff --git a/Android.mk b/Android.mk
index 5e94479f69d14e..6cf1fd55e33ff3 100644
--- a/Android.mk
+++ b/Android.mk
@@ -8,8 +8,11 @@
 # which prevents the Android build system from mistakenly loading any other
 # Android.mk that may exist in the Chromium tree.
 
-ifdef CHROME_ANDROID_BUILD_WEBVIEW
-CHROMIUM_WEBVIEW_DIR := $(call my-dir)
-include $(CHROMIUM_WEBVIEW_DIR)/GypAndroid.mk
-include $(CHROMIUM_WEBVIEW_DIR)/android_webview/Android.mk
+CHROMIUM_DIR := $(call my-dir)
+
+# Assume that if the gyp autogenerated makefile exists, we are doing the
+# WebView build using the Android build system.
+ifneq (,$(wildcard $(CHROMIUM_DIR)/GypAndroid.mk))
+include $(CHROMIUM_DIR)/GypAndroid.mk
+include $(CHROMIUM_DIR)/android_webview/Android.mk
 endif