[Android WebView] Propagate Java exceptions from JS dialog callbacks

android_webview/java/src/org/chromium/android_webview/AwContentsClientBridge.java

Index: android_webview/java/src/org/chromium/android_webview/AwContentsClientBridge.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContentsClientBridge.java b/android_webview/java/src/org/chromium/android_webview/AwContentsClientBridge.java
index a294913efc1270ead695e6a680faae6726f85b01..d2207f4cd61c8dde28d77a82565802d48e6ab848 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContentsClientBridge.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContentsClientBridge.java
@@ -7,6 +7,7 @@ package org.chromium.android_webview;
 import android.content.Context;
 import android.net.http.SslCertificate;
 import android.net.http.SslError;
+import android.os.Handler;
 import android.util.Log;
 import android.webkit.ValueCallback;
 
@@ -231,21 +232,49 @@ public class AwContentsClientBridge {
     }
 
     @CalledByNative
-    private void handleJsAlert(String url, String message, int id) {
-        JsResultHandler handler = new JsResultHandler(this, id);
-        mClient.handleJsAlert(url, message, handler);
+    private void handleJsAlert(final String url, final String message, final int id) {
+        // Post the application callback back to the current thread to ensure the application
+        // callback is executed without any native code on the stack. This so that any exception
+        // thrown by the application callback won't have to be propagated through a native call
+        // stack.
+        new Handler().post(new Runnable() {
+            @Override
+            public void run() {
+                JsResultHandler handler = new JsResultHandler(AwContentsClientBridge.this, id);
+                mClient.handleJsAlert(url, message, handler);
+            }
+        });
     }
 
     @CalledByNative
-    private void handleJsConfirm(String url, String message, int id) {
-        JsResultHandler handler = new JsResultHandler(this, id);
-        mClient.handleJsConfirm(url, message, handler);
+    private void handleJsConfirm(final String url, final String message, final int id) {
+        // Post the application callback back to the current thread to ensure the application
+        // callback is executed without any native code on the stack. This so that any exception
+        // thrown by the application callback won't have to be propagated through a native call
+        // stack.
+        new Handler().post(new Runnable() {
+            @Override
+            public void run() {
+                JsResultHandler handler = new JsResultHandler(AwContentsClientBridge.this, id);
+                mClient.handleJsConfirm(url, message, handler);
+            }
+        });
     }
 
     @CalledByNative
-    private void handleJsPrompt(String url, String message, String defaultValue, int id) {
-        JsResultHandler handler = new JsResultHandler(this, id);
-        mClient.handleJsPrompt(url, message, defaultValue, handler);
+    private void handleJsPrompt(
+            final String url, final String message, final String defaultValue, final int id) {
+        // Post the application callback back to the current thread to ensure the application
+        // callback is executed without any native code on the stack. This so that any exception
+        // thrown by the application callback won't have to be propagated through a native call
+        // stack.
+        new Handler().post(new Runnable() {
+            @Override
+            public void run() {
+                JsResultHandler handler = new JsResultHandler(AwContentsClientBridge.this, id);
+                mClient.handleJsPrompt(url, message, defaultValue, handler);
+            }
+        });
     }
 
     @CalledByNative