[Android] Expose showFileChooser in AwContentsClient interface

android_webview/java/src/org/chromium/android_webview/AwWebContentsDelegate.java

Index: android_webview/java/src/org/chromium/android_webview/AwWebContentsDelegate.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwWebContentsDelegate.java b/android_webview/java/src/org/chromium/android_webview/AwWebContentsDelegate.java
index 23f48ebfee447459acda72d290738c76dc3ca034..d26fd9abe582ee34832ca06bb0916d60ac9538fc 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwWebContentsDelegate.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwWebContentsDelegate.java
@@ -4,6 +4,8 @@
 
 package org.chromium.android_webview;
 
+import com.google.common.annotations.VisibleForTesting;
+
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
 import org.chromium.components.web_contents_delegate_android.WebContentsDelegateAndroid;
@@ -14,8 +16,14 @@ import org.chromium.components.web_contents_delegate_android.WebContentsDelegate
  * It should contain abstract WebContentsDelegate methods to be implemented by the embedder.
  * These methods belong to WebView but are not shared with the Chromium Android port.
  */
+@VisibleForTesting
 @JNINamespace("android_webview")
 public abstract class AwWebContentsDelegate extends WebContentsDelegateAndroid {
+    // Callback filesSelectedInChooser() when done.
+    @CalledByNative
+    public abstract void runFileChooser(int processId, int renderId, int mode_flags,
+            String acceptTypes, String title, String defaultFilename,  boolean capture);
+
     @CalledByNative
     public abstract boolean addNewContents(boolean isDialog, boolean isUserGesture);
 
@@ -33,4 +41,8 @@ public abstract class AwWebContentsDelegate extends WebContentsDelegateAndroid {
     @CalledByNative
     public void updatePreferredSize(int widthCss, int heightCss) {
     }
+
+    // Call in response to a prior runFileChooser call.
+    protected static native void nativeFilesSelectedInChooser(int processId, int renderId,
+            int mode_flags, String[] filePath);
 }