Fix a crash due to NullPointerException

This NullPointerException should be really rare. There is a fix on
the way, for now we just catch the exception to prevent crash.

Bug: 842059
Change-Id: Ie130d887d303e7f08504b8c783ae43b87ed31ccf
Reviewed-on: https://chromium-review.googlesource.com/1057427Reviewed-by: Amirhossein Simjour <asimjour@chromium.org>
Commit-Queue: Biao She <bshe@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558398}

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesWrapperImpl.java

@@ -75,7 +75,12 @@ public class VrClassesWrapperImpl implements VrClassesWrapper {
         Context context = ContextUtils.getApplicationContext();
         // The call to isInVrSession crashes when called on a non-Daydream ready device, so we add
         // the device check (b/77268533).
-        return isDaydreamReadyDevice() && DaydreamApi.isInVrSession(context);
+        try {
+          return isDaydreamReadyDevice() && DaydreamApi.isInVrSession(context);
+        } catch (Exception ex) {
+          Log.e(TAG, "Unable to check if in vr session", ex);
+          return false;
+        }
     }
 
     @Override