Bug 1252650 - Add GeckoThread.canUseProfile; r=snorp

canUseProfile returns whether we're currently using the given profile or
we can potentially start Gecko with the given profile.

mobile/android/base/java/org/mozilla/gecko/GeckoThread.java

@@ -130,17 +130,10 @@ public class GeckoThread extends Thread {
         return false;
     }
 
-    public static boolean initWithProfile(String profileName, File profileDir) {
-        if (profileName == null) {
-            throw new IllegalArgumentException("Null profile name");
-        }
-
-        final GeckoProfile profile = getActiveProfile();
+    private static boolean canUseProfile(final GeckoProfile profile, final String profileName,
+                                         final File profileDir) {
         if (profile == null) {
-            // We haven't initialized yet; okay to initialize now.
-            final Context context = GeckoAppShell.getApplicationContext();
-            return init(GeckoProfile.get(context, profileName, profileDir),
-                        /* args */ null, /* action */ null, /* debugging */ false);
+            return true;
         }
 
         // We already initialized and have a profile; see if it matches ours.
@@ -153,6 +146,29 @@ public class GeckoThread extends Thread {
         }
     }
 
+    public static boolean canUseProfile(final String profileName, final File profileDir) {
+        if (profileName == null) {
+            throw new IllegalArgumentException("Null profile name");
+        }
+        return canUseProfile(getActiveProfile(), profileName, profileDir);
+    }
+
+    public static boolean initWithProfile(final String profileName, final File profileDir) {
+        if (profileName == null) {
+            throw new IllegalArgumentException("Null profile name");
+        }
+
+        final GeckoProfile profile = getActiveProfile();
+        if (profile != null) {
+            return canUseProfile(profile, profileName, profileDir);
+        }
+
+        // We haven't initialized yet; okay to initialize now.
+        final Context context = GeckoAppShell.getApplicationContext();
+        return init(GeckoProfile.get(context, profileName, profileDir),
+                    /* args */ null, /* action */ null, /* debugging */ false);
+    }
+
     public static boolean launch() {
         ThreadUtils.assertOnUiThread();
         if (checkAndSetState(State.INITIAL, State.LAUNCHED)) {