Clean visual style, part II: extend bright style, convert icons, more touch-ups.

This commit removes the remaining white icons from the previous style,
which was a mix of 'holo dark' (i.e. light) icons and other un-fitting
icons. It's all replaced with theme-colored icons.

The primary color itself had been altered a bit towards green (#18aba1).
Other than the icon replacements, this commit changes:
 - tab switcher: fix cosmetic bug in the title bar in <= xhdpi devices
 - tab switcher: better incognito presentation
 - settings: enable back (<-) arrow
 - settings: bold color in the activity (on L and up)
 - settings: rationalized launching
 - better spacings on the mobile title bar
 - better padding on history items
 - add proportional padding (1em) to the incognito page
 - the incognito tab bar gets a bit darker
 - ['Ingnito Page', 'New Incognito Tab'] -> 'Private Browsing'
 - 'Page info' -> 'Page information' (no abbrevs when user facing :)

Vast amount of unused resources are removed from the APK.

Change-Id: I4add15fc686495ce27f63e26c2c56c14fa3d6603
diff --git a/src/com/android/browser/BrowserActivity.java b/src/com/android/browser/BrowserActivity.java
index 4b9f48c..8569550 100644
--- a/src/com/android/browser/BrowserActivity.java
+++ b/src/com/android/browser/BrowserActivity.java
@@ -276,7 +276,10 @@
             Log.v(LOGTAG, "BrowserActivity.onDestroy: this=" + this);
         }
         super.onDestroy();
-        mEngineInitializer.onActivityDestroy();
+        // mEngineInitializer can be null if onCreate is not called before onDestroy
+        // it happens when starting the activity with an intent while the screen is locked.
+        if (mEngineInitializer != null)
+            mEngineInitializer.onActivityDestroy();
         mController.onDestroy();
         mController = NullController.INSTANCE;
     }