Remove unused context in ChromePreferenceManager.

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SignInPromo.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SignInPromo.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SignInPromo.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SignInPromo.java
index ca08ef422fb75ba3592e37207212471a86ef8db0..b4777bc0ed18a2626ccbd8162acd8ee7bd6ff3bd 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SignInPromo.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SignInPromo.java
@@ -44,8 +44,7 @@ public class SignInPromo extends OptionalLeaf
     private final SigninObserver mObserver;
 
     public SignInPromo(SuggestionsUiDelegate uiDelegate) {
-        mDismissed = ChromePreferenceManager.getInstance(ContextUtils.getApplicationContext())
-                             .getNewTabPageSigninPromoDismissed();
+        mDismissed = ChromePreferenceManager.getInstance().getNewTabPageSigninPromoDismissed();
 
         SigninManager signinManager = SigninManager.get(ContextUtils.getApplicationContext());
         if (mDismissed) {
@@ -125,8 +124,7 @@ public class SignInPromo extends OptionalLeaf
         mDismissed = true;
         setVisible(false);
 
-        ChromePreferenceManager.getInstance(ContextUtils.getApplicationContext())
-                .setNewTabPageSigninPromoDismissed(true);
+        ChromePreferenceManager.getInstance().setNewTabPageSigninPromoDismissed(true);
         mObserver.unregister();
         itemRemovedCallback.onResult(ContextUtils.getApplicationContext().getString(getHeader()));
     }