Add the ability to configure feedback prompt frequency

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

Index: chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrFeedbackStatus.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrFeedbackStatus.java b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrFeedbackStatus.java
index 3a87656bbe412be16fa8d7c3bf3c1e33618c54c7..5967ab6140a8c38161e219f62355c011366d1cd9 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrFeedbackStatus.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrFeedbackStatus.java
@@ -5,13 +5,26 @@
 package org.chromium.chrome.browser.vr_shell;
 
 import org.chromium.base.ContextUtils;
+import org.chromium.chrome.browser.ChromeFeatureList;
 
 /**
  * Gets and sets preferences related to the status of the Vr feedback infobar.
  */
 public class VrFeedbackStatus {
-    public static final String VR_FEEDBACK_OPT_OUT = "VR_FEEDBACK_OPT_OUT";
-    public static final String VR_EXIT_TO_2D_COUNT = "VR_EXIT_TO_2D_COUNT";
+    private static final String FEEDBACK_FREQUENCY_PARAM_NAME = "feedback_frequency";
+    private static final int DEFAULT_FEEDBACK_FREQUENCY = 10;
+
+    private static final String VR_FEEDBACK_OPT_OUT = "VR_FEEDBACK_OPT_OUT";
+    private static final String VR_EXIT_TO_2D_COUNT = "VR_EXIT_TO_2D_COUNT";
+
+    /**
+     * Returns how often we should show the feedback prompt.
+     */
+    public static int getFeedbackFrequency() {
+        return ChromeFeatureList.getFieldTrialParamByFeatureAsInt(
+                ChromeFeatureList.VR_BROWSING_FEEDBACK, FEEDBACK_FREQUENCY_PARAM_NAME,
+                DEFAULT_FEEDBACK_FREQUENCY);
+    }
 
     /**
      * Sets the "opted out of entering VR feedback" preference.
@@ -46,4 +59,4 @@ public class VrFeedbackStatus {
     public static int getUserExitedAndEntered2DCount() {
         return ContextUtils.getAppSharedPreferences().getInt(VR_EXIT_TO_2D_COUNT, 0);
     }
-}
+}