Initial implementation of the useragent switcher

Change-Id: Iaa8262a678902645dbfaa8a53fe7212af7d9d53c
diff --git a/res/drawable-mdpi/ic_ua_android.png b/res/drawable-mdpi/ic_ua_android.png
new file mode 100644
index 0000000..4f7aa45
--- /dev/null
+++ b/res/drawable-mdpi/ic_ua_android.png
Binary files differ
diff --git a/res/drawable-mdpi/ic_ua_desktop.png b/res/drawable-mdpi/ic_ua_desktop.png
new file mode 100644
index 0000000..4e2f5c2
--- /dev/null
+++ b/res/drawable-mdpi/ic_ua_desktop.png
Binary files differ
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 90c6cc1..ad8f64d 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -657,10 +657,15 @@
     <string name="pref_use_instant_search_summary">
       Use Google Instant when you use Google Search, to show results as you
       type (this can increase data use).</string>
+    <!-- Title for the fullscreen lab feature [CHAR LIMIT=40] -->
     <string name="pref_lab_fullscreen">Fullscreen</string>
     <!-- Summary for the fullscreen lab feature [CHAR LIMIT=120] -->
     <string name="pref_lab_fullscreen_summary">
       Use fullscreen mode to hide the status bar.</string>
+    <!-- Title for the useragent switcher lab feature [CHAR LIMIT=40] -->
+    <string name="pref_enable_useragent_switcher">Useragent Switcher</string>
+    <!-- Summary for the useragent switcher lab feature [CHAR LIMIT=120] -->
+    <string name="pref_enable_useragent_switcher_summary">Toggle between tablet and desktop versions of a site (per tab)</string>
 
     <!-- Title for a dialog displayed when the browser has a data connectivity
             problem -->
diff --git a/res/xml-xlarge/lab_preferences.xml b/res/xml-sw600dp/lab_preferences.xml
similarity index 85%
rename from res/xml-xlarge/lab_preferences.xml
rename to res/xml-sw600dp/lab_preferences.xml
index 87383b0..c858c38 100644
--- a/res/xml-xlarge/lab_preferences.xml
+++ b/res/xml-sw600dp/lab_preferences.xml
@@ -34,4 +34,10 @@
         android:defaultValue="false"
         android:title="@string/pref_use_instant_search"
         android:summary="@string/pref_use_instant_search_summary" />
+
+    <CheckBoxPreference
+        android:key="enable_useragent_switcher"
+        android:defaultValue="false"
+        android:title="@string/pref_enable_useragent_switcher"
+        android:summary="@string/pref_enable_useragent_switcher_summary" />
 </PreferenceScreen>