[Android] Show document mode opt-out InfoBar on selected devices.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/preferences/DocumentModeManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/DocumentModeManager.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/DocumentModeManager.java
index 58914a3f5c108b992321a145ce2e8c74696faa95..8dabea3428f2a309411237ffcfb0b7145f9541c3 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/preferences/DocumentModeManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/DocumentModeManager.java
@@ -169,6 +169,7 @@ public class DocumentModeManager {
     };
 
     private static DocumentModeManager sManager;
+    private static Boolean sIsDeviceTabbedModeByDefaultCache;
 
     private final SharedPreferences mSharedPreferences;
 
@@ -197,6 +198,13 @@ public class DocumentModeManager {
     }
 
     /**
+     * @return Whether the user set a preference to use the document mode.
+     */
+    public boolean isOptedInToDocumentMode() {
+        return getOptOutState() == OPT_IN_TO_DOCUMENT_MODE;
+    }
+
+    /**
      * @return Whether the user dismissed the opt out promo.
      */
     public boolean isOptOutPromoDismissed() {
@@ -254,10 +262,18 @@ public class DocumentModeManager {
      *         platform Overview screen is deemed too difficult to make Document mode user friendly.
      */
     public static boolean isDeviceTabbedModeByDefault() {
+        if (sIsDeviceTabbedModeByDefaultCache != null) {
+            return sIsDeviceTabbedModeByDefaultCache.booleanValue();
+        }
+
         String model = Build.MODEL.toUpperCase(Locale.US);
         for (String device : DEFAULT_TABBED_MODE_DEVICES) {
-            if (model.contains(device)) return true;
+            if (model.contains(device)) {
+                sIsDeviceTabbedModeByDefaultCache = Boolean.TRUE;
+                return true;
+            }
         }
+        sIsDeviceTabbedModeByDefaultCache = Boolean.FALSE;
         return false;
     }