Post destroy() to UI thread

Fix for bug 10647580, could not reproduce locally.

Change-Id: I2812a448c44da694249f355ad1f20b941b86d3ab
diff --git a/chromium/java/com/android/webview/chromium/WebViewChromium.java b/chromium/java/com/android/webview/chromium/WebViewChromium.java
index 7eff33b..94bb6bf 100644
--- a/chromium/java/com/android/webview/chromium/WebViewChromium.java
+++ b/chromium/java/com/android/webview/chromium/WebViewChromium.java
@@ -233,7 +233,16 @@
 
     @Override
     public void destroy() {
-        checkThread();
+        if (!ThreadUtils.runningOnUiThread()) {
+            ThreadUtils.postOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    destroy();
+                }
+            });
+            return;
+        }
+
         mAwContents.destroy();
         if (mGLfunctor != null) {
             mGLfunctor.destroy();