[WebView] Allow the WebView to be compiled against the system SDK.

BUG:18152150
Change-Id: Ifd6dcac17663631058d895c61bb6e8018c5aeecc
diff --git a/core/java/android/webkit/WebChromeClient.java b/core/java/android/webkit/WebChromeClient.java
index 46a7fd0..768dc9f 100644
--- a/core/java/android/webkit/WebChromeClient.java
+++ b/core/java/android/webkit/WebChromeClient.java
@@ -16,6 +16,7 @@
 
 package android.webkit;
 
+import android.annotation.SystemApi;
 import android.content.Intent;
 import android.content.pm.ActivityInfo;
 import android.graphics.Bitmap;
@@ -509,6 +510,7 @@
      * @deprecated Use {@link #showFileChooser} instead.
      * @hide This method was not published in any SDK version.
      */
+    @SystemApi
     @Deprecated
     public void openFileChooser(ValueCallback<Uri> uploadFile, String acceptType, String capture) {
         uploadFile.onReceiveValue(null);