Add a LocationUtils class to give all Chromium Android code access to location helpers.

components/location/android/java/src/org/chromium/components/location/LocationUtils.java

Index: components/location/android/java/src/org/chromium/components/location/LocationUtils.java
diff --git a/components/location/android/java/src/org/chromium/components/location/LocationUtils.java b/components/location/android/java/src/org/chromium/components/location/LocationUtils.java
new file mode 100644
index 0000000000000000000000000000000000000000..f9e0899f53ef3ccbdfe084d70c926c7bd5f5c3b5
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+++ b/components/location/android/java/src/org/chromium/components/location/LocationUtils.java
@@ -0,0 +1,104 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.components.location;
+
+import android.Manifest;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.os.Build;
+import android.os.Process;
+import android.provider.Settings;
+import android.text.TextUtils;
+
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.VisibleForTesting;
+import org.chromium.base.annotations.SuppressFBWarnings;
+
+/**
+ * Provides methods for querying Chrome's ability to use Android's location services.
+ *
+ * This class should be used only on the UI thread.
+ */
+public class LocationUtils {
+    // Used to construct sInstance if that's null.
+    private static Factory sFactory;
+
+    private static LocationUtils sInstance;
+
+    protected LocationUtils() {}
+
+    /**
+     * Returns the singleton instance of LocationSettings, creating it if needed.
+     */
+    @SuppressFBWarnings("LI_LAZY_INIT_STATIC")
+    public static LocationUtils getInstance() {
+        ThreadUtils.assertOnUiThread();
+        if (sInstance == null) {
+            if (sFactory == null) {
+                sInstance = new LocationUtils();
+            } else {
+                sInstance = sFactory.create();
+            }
+        }
+        return sInstance;
+    }
+
+    private boolean hasPermission(Context context, String name) {
+        return context.checkPermission(name, Process.myPid(), Process.myUid())
+                == PackageManager.PERMISSION_GRANTED;
+    }
+
+    /**
+     * Returns true if Chromium has permission to access location.
+     *
+     * Check both hasAndroidLocationPermission() and isSystemLocationSettingEnabled() to determine
+     * if Chromium's location requests will return results.
+     */
+    public boolean hasAndroidLocationPermission(Context context) {
+        return hasPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION)
+                || hasPermission(context, Manifest.permission.ACCESS_FINE_LOCATION);
+    }
+
+    /**
+     * Returns whether location services are enabled system-wide, i.e. whether any application is
+     * able to access location.
+     */
+    public boolean isSystemLocationSettingEnabled(Context context) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
+            return Settings.Secure.getInt(context.getContentResolver(),
+                           Settings.Secure.LOCATION_MODE, Settings.Secure.LOCATION_MODE_OFF)
+                    != Settings.Secure.LOCATION_MODE_OFF;
+        } else {
+            return !TextUtils.isEmpty(Settings.Secure.getString(
+                    context.getContentResolver(), Settings.Secure.LOCATION_PROVIDERS_ALLOWED));
+        }
+    }
+
+    /**
+     * Returns an intent to launch Android Location Settings.
+     */
+    public Intent getSystemLocationSettingsIntent() {
+        Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
+        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        return i;
+    }
+
+    /**
+     * Instantiate this to explain how to create a LocationUtils instance in
+     * LocationUtils.getInstance().
+     */
+    public interface Factory { public LocationUtils create(); }
+
+    /**
+     * Call this to use a different subclass of LocationUtils throughout the program.
+     * This can be used by embedders in addition to tests.
+     */
+    @VisibleForTesting
+    public static void setFactory(Factory factory) {
+        sFactory = factory;
+        sInstance = null;
+    }
+}