WebVR: enable Cardboard button compatibility

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 48a19ba7428bd18e1c01cffffc3b08cfa2120c9f..71801447f03ddb7c58dd5fdb27b0d5d234450696 100644
--- a/chrome/browser/android/vr_shell/vr_shell.cc
+++ b/chrome/browser/android/vr_shell/vr_shell.cc
@@ -593,6 +593,19 @@ void VrShell::DrawFrame(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   if (html_interface_->GetMode() == UiInterface::Mode::WEB_VR) {
     DrawWebVr();
 
+    // Process screen touch events for Cardboard button compatibility.
+    if (touch_pending_) {

[bajones, 2016/11/17 20:42:53]

Shouldn't this go in UpdateController under the if (html_interface_->GetMode()
== UiInterface::Mode::WEB_VR) branch?

[klausw, 2016/11/17 21:00:00]

Yes, that's a much better fit. Moved.

+      touch_pending_ = false;
+      std::unique_ptr<WebGestureEvent> gesture(new WebGestureEvent());
+      gesture->sourceDevice = blink::WebGestureDeviceTouchpad;
+      gesture->timeStampSeconds =
+          (base::TimeTicks::Now() - base::TimeTicks()).InSecondsF();
+      gesture->type = WebInputEvent::GestureTapDown;
+      gesture->data.tapDown.width = 0;
+      gesture->data.tapDown.height = 0;
+      content_input_manager_->ProcessUpdatedGesture(*gesture.get());
+    }
+
     // When using async reprojection, we need to know which pose was used in
     // the WebVR app for drawing this frame. Due to unknown amounts of
     // buffering in the compositor and SurfaceTexture, we read the pose number