AW: Add reload menu to SystemWebViewShell

This feature will make the related test easy.

Change-Id: I93835a5ccdf7b3adea6e360e980432e482ddb1d8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2405704Reviewed-by: Tim Volodine <timvolodine@chromium.org>
Commit-Queue: Michael Bai <michaelbai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807941}

android_webview/tools/system_webview_shell/apk/res/menu/main_menu.xml

@@ -4,6 +4,8 @@
      found in the LICENSE file. -->
 
 <menu xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:id="@+id/menu_reload_webview"
+          android:title="@string/menu_reload_webview"/>
     <item android:id="@+id/menu_reset_webview"
           android:title="@string/menu_reset_webview"/>
     <item android:id="@+id/menu_clear_cache"

android_webview/tools/system_webview_shell/apk/res/values/strings.xml

@@ -15,6 +15,7 @@
     <string name="title_activity_thread_test">WebView Thread Test</string>
     <string name="title_activity_page_cycler">WebView Page Cycler Test</string>
     <string name="title_activity_create_destroy">WebView Create Destroy</string>
+    <string name="menu_reload_webview">Reload</string>
     <string name="menu_reset_webview">Destroy and create new WebView</string>
     <string name="menu_clear_cache">Clear cache</string>
     <string name="menu_enable_tracing">Enable tracing</string>

android_webview/tools/system_webview_shell/apk/src/org/chromium/webview_shell/WebViewBrowserActivity.java

@@ -605,7 +605,9 @@ public class WebViewBrowserActivity extends AppCompatActivity {
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         int itemId = item.getItemId();
-        if (itemId == R.id.menu_reset_webview) {
+        if (itemId == R.id.menu_reload_webview) {
+            if (mWebView != null) mWebView.reload();
+        } else if (itemId == R.id.menu_reset_webview) {
             if (mWebView != null) {
                 ViewGroup container = getContainer();
                 container.removeView(mWebView);