[Android WebView] Plumb WebContentsDelegate::CloseContents to embedder.

android_webview/java/src/org/chromium/android_webview/AwContentsClient.java

Index: android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java b/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
index 1eaeafc0c49d3e6e11541d30885a2540c60763f6..3da0d6fd16e1f7b561722cb95834910aadb2e405 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
@@ -123,7 +123,7 @@ public abstract class AwContentsClient extends ContentViewClient {
 
         @Override
         public void closeContents() {
-            // TODO: implement
+            AwContentsClient.this.onCloseWindow();
         }
 
         @Override
@@ -137,7 +137,6 @@ public abstract class AwContentsClient extends ContentViewClient {
         public boolean addNewContents(boolean isDialog, boolean isUserGesture) {
             return AwContentsClient.this.onCreateWindow(isDialog, isUserGesture);
         }
-
     }
 
     class AwWebContentsObserver extends WebContentsObserverAndroid {
@@ -216,6 +215,8 @@ public abstract class AwContentsClient extends ContentViewClient {
 
     protected abstract boolean onCreateWindow(boolean isDialog, boolean isUserGesture);
 
+    protected abstract void onCloseWindow();
+
     //--------------------------------------------------------------------------------------------
     //                              Other WebView-specific methods
     //--------------------------------------------------------------------------------------------