Revert "[Home] Save Chrome Home enabled date in SharedPreference"

This reverts commit b4e76580.

Reason for revert: Crashing on ToT

Original change's description:
> [Home] Save Chrome Home enabled date in SharedPreference
> 
> Saves the current date in a SharedPreference when Chrome Home is first enabled. 
> Removes the preference if Chrome Home is disabled.
> 
> Bug: 739952
> Change-Id: I6f0b1bd9693a7532616bdda8b4ad4bf74fdadaef
> Reviewed-on: https://chromium-review.googlesource.com/663832
> Commit-Queue: Daniel Park <danielpark@chromium.org>
> Reviewed-by: Ted Choc <tedchoc@chromium.org>
> Reviewed-by: Theresa <twellington@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#502752}

TBR=tedchoc@chromium.org,twellington@chromium.org,danielpark@chromium.org

Change-Id: I4af618be0a96f6e0deb0a5b3fb152749c6a4c5ef
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 739952
Reviewed-on: https://chromium-review.googlesource.com/673025Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#502868}

chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceManager.java

@@ -5,7 +5,6 @@
 package org.chromium.chrome.browser.preferences;
 
 import android.content.SharedPreferences;
-import android.os.StrictMode;
 
 import org.chromium.base.ContextUtils;
 import org.chromium.base.annotations.SuppressFBWarnings;
@@ -62,8 +61,6 @@ public class ChromePreferenceManager {
 
     private static final String OMNIBOX_PLACEHOLDER_GROUP = "omnibox-placeholder-group";
 
-    private static final String CHROME_HOME_SHARED_PREFERENCES_KEY = "chrome_home_enabled_date";
-
     private static ChromePreferenceManager sPrefs;
 
     private final SharedPreferences mSharedPreferences;
@@ -483,28 +480,4 @@ public class ChromePreferenceManager {
         ed.putBoolean(key, value);
         ed.apply();
     }
-
-    /**
-     * Logs the most recent date that Chrome Home was enabled.
-     * Removes the entry if Chrome Home is disabled.
-     *
-     * @param isChromeHomeEnabled Whether or not Chrome Home is currently enabled.
-     */
-    public static void setChromeHomeEnabledDate(boolean isChromeHomeEnabled) {
-        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
-        try {
-            SharedPreferences sharedPreferences = ContextUtils.getAppSharedPreferences();
-            String earliestLoggedDate =
-                    sharedPreferences.getString(CHROME_HOME_SHARED_PREFERENCES_KEY, null);
-            if (isChromeHomeEnabled && earliestLoggedDate == null) {
-                sharedPreferences.edit()
-                        .putLong(CHROME_HOME_SHARED_PREFERENCES_KEY, System.currentTimeMillis())
-                        .apply();
-            } else if (!isChromeHomeEnabled && earliestLoggedDate != null) {
-                sharedPreferences.edit().remove(CHROME_HOME_SHARED_PREFERENCES_KEY).apply();
-            }
-        } finally {
-            StrictMode.setThreadPolicy(oldPolicy);
-        }
-    }
 }

chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java

@@ -270,19 +270,21 @@ public class FeatureUtilities {
             } finally {
                 StrictMode.setThreadPolicy(oldPolicy);
             }
+
             // If the browser has been initialized by this point, check the experiment as well to
             // avoid the restart logic in cacheChromeHomeEnabled.
             if (ChromeFeatureList.isInitialized()) {
                 boolean chromeHomeExperimentEnabled =
                         ChromeFeatureList.isEnabled(ChromeFeatureList.CHROME_HOME);
+
                 if (chromeHomeExperimentEnabled != sChromeHomeEnabled) {
                     sChromeHomeEnabled = chromeHomeExperimentEnabled;
                     ChromePreferenceManager.getInstance().setChromeHomeEnabled(
                             chromeHomeExperimentEnabled);
                 }
             }
-            ChromePreferenceManager.setChromeHomeEnabledDate(sChromeHomeEnabled);
         }
+
         return sChromeHomeEnabled;
     }