Handle basic navigation controls without webcontents in VR Shell.

chrome/browser/android/vr_shell/vr_shell.cc

Index: chrome/browser/android/vr_shell/vr_shell.cc
diff --git a/chrome/browser/android/vr_shell/vr_shell.cc b/chrome/browser/android/vr_shell/vr_shell.cc
index 2e8fba0709b366f185af5a76031929bcea3cb4e0..974f167258de82f2deaad5885a55e2c0f81286ae 100644
--- a/chrome/browser/android/vr_shell/vr_shell.cc
+++ b/chrome/browser/android/vr_shell/vr_shell.cc
@@ -408,6 +408,7 @@ void VrShell::UpdateScene(const base::ListValue* args) {
 
 void VrShell::DoUiAction(const UiAction action,
                          const base::DictionaryValue* arguments) {
+  // Actions that can be handled natively.
   switch (action) {
     case OMNIBOX_CONTENT:
       html_interface_->HandleOmniboxInput(*arguments);
@@ -418,50 +419,48 @@ void VrShell::DoUiAction(const UiAction action,
       SetContentPaused(paused);
       return;
     }
+    case HISTORY_BACK:
+      if (main_contents_ && main_contents_->IsFullscreen()) {
+        main_contents_->ExitFullscreen(false);
+        return;
+      }
+      // Otherwise handle in java.
+      break;
+    case ZOOM_OUT:  // Not handled yet.
+    case ZOOM_IN:   // Not handled yet.
+      return;
+#if defined(ENABLE_VR_SHELL_UI_DEV)
+    case RELOAD_UI:
+      ui_contents_->GetController().Reload(content::ReloadType::NORMAL, false);
+      html_interface_.reset(new UiInterface(UiInterface::Mode::STANDARD));
+      SetUiState();
+      vr_web_contents_observer_->SetUiInterface(html_interface_.get());
+      return;
+#endif
     default:
       break;
   }
-  // TODO(mthiesse): Handles these in java through the Tab.
-  if (!main_contents_)
-    return;
-  content::NavigationController& controller = main_contents_->GetController();
+  // Actions that are handled in java.
+  JNIEnv* env = base::android::AttachCurrentThread();
   switch (action) {
     case HISTORY_BACK:
-      if (main_contents_->IsFullscreen()) {
-        main_contents_->ExitFullscreen(false);
-      } else if (controller.CanGoBack()) {
-        controller.GoBack();
-      }
+      Java_VrShellImpl_navigateBack(env, j_vr_shell_.obj());
       break;
     case HISTORY_FORWARD:
-      if (controller.CanGoForward())
-        controller.GoForward();
+      Java_VrShellImpl_navigateForward(env, j_vr_shell_.obj());
       break;
     case RELOAD:
-      controller.Reload(content::ReloadType::NORMAL, false);
+      Java_VrShellImpl_reload(env, j_vr_shell_.obj());
       break;
     case LOAD_URL: {
-      std::string url_string;
+      base::string16 url_string;
       CHECK(arguments->GetString("url", &url_string));
-      GURL url(url_string);
-      // TODO(crbug.com/683344): Sanitize the URL and prefix, and pass the
-      // proper transition type down from the UI.
-      controller.LoadURL(url, content::Referrer(),
-                         ui::PageTransition::PAGE_TRANSITION_AUTO_TOPLEVEL,
-                         std::string(""));
+      base::android::ScopedJavaLocalRef<jstring> string =
+          base::android::ConvertUTF16ToJavaString(env, url_string);
+      Java_VrShellImpl_loadURL(env, j_vr_shell_.obj(), string,
+                               ui::PageTransition::PAGE_TRANSITION_TYPED);
       break;
     }
-#if defined(ENABLE_VR_SHELL_UI_DEV)
-    case RELOAD_UI:
-      ui_contents_->GetController().Reload(content::ReloadType::NORMAL, false);
-      html_interface_.reset(new UiInterface(UiInterface::Mode::STANDARD));
-      SetUiState();
-      vr_web_contents_observer_->SetUiInterface(html_interface_.get());
-      break;
-#endif
-    case ZOOM_OUT:  // Not handled yet.
-    case ZOOM_IN:  // Not handled yet.
-      break;
     default:
       NOTREACHED();
   }