Clean visual style: move to Light, add Material support, change Drawables (progress, icons).

This code alters the visual style moving the APP to a Light theme.
Parents of the theme are either Theme.Holo.Light or Theme.Material.Light
depending on which API we start the APK from. Needs SDK 21 to build.

Other than the visual changes, this commit changes:
 - name of the APP to 'Browser'
 - animations and sequencing of the Tab switcher in {nav/anim}_screen
 - removal of the warning icon from the Exit dialog
 - change of the favicon appearance (removal of the double border)

Vast amount of unused resources are removed from the APK. Just XHDPI
drawables have been synthesized for now, and the Primary color was
used for the icons and is accessible in R.color.Primary.

Change-Id: If75cc051c5d4015383e96066cdb6507484e625d8
diff --git a/src/com/android/browser/NavigationBarTablet.java b/src/com/android/browser/NavigationBarTablet.java
index a965e0a..17f7398 100644
--- a/src/com/android/browser/NavigationBarTablet.java
+++ b/src/com/android/browser/NavigationBarTablet.java
@@ -31,7 +31,6 @@
 import android.widget.ImageButton;
 import android.widget.ImageView;
 
-import com.android.browser.R;
 import com.android.browser.UI.ComboViews;
 import com.android.browser.UrlInputView.StateListener;
 
@@ -53,8 +52,6 @@
     private View mClearButton;
     private View mVoiceButton;
     private View mNavButtons;
-    private Drawable mFocusDrawable;
-    private Drawable mUnfocusDrawable;
     private boolean mHideNavButtons;
     private Drawable mFaviconDrawable;
 
@@ -75,14 +72,10 @@
 
     private void init(Context context) {
         Resources resources = context.getResources();
-        mStopDrawable = resources.getDrawable(R.drawable.ic_stop_holo_dark);
-        mReloadDrawable = resources.getDrawable(R.drawable.ic_refresh_holo_dark);
+        mStopDrawable = resources.getDrawable(R.drawable.ic_action_stop);
+        mReloadDrawable = resources.getDrawable(R.drawable.ic_action_reload);
         mStopDescription = resources.getString(R.string.accessibility_button_stop);
         mRefreshDescription = resources.getString(R.string.accessibility_button_refresh);
-        mFocusDrawable = resources.getDrawable(
-                R.drawable.textfield_active_holo_dark);
-        mUnfocusDrawable = resources.getDrawable(
-                R.drawable.textfield_default_holo_dark);
         mHideNavButtons = resources.getBoolean(R.bool.hide_nav_buttons);
     }
 
@@ -140,12 +133,8 @@
 
     void updateNavigationState(Tab tab) {
         if (tab != null) {
-            mBackButton.setImageResource(tab.canGoBack()
-                    ? R.drawable.ic_back_holo_dark
-                    : R.drawable.ic_back_disabled_holo_dark);
-            mForwardButton.setImageResource(tab.canGoForward()
-                    ? R.drawable.ic_forward_holo_dark
-                    : R.drawable.ic_forward_disabled_holo_dark);
+            mBackButton.setEnabled(tab.canGoBack());
+            mForwardButton.setEnabled(tab.canGoBack());
         }
         updateUrlIcon();
     }
@@ -205,7 +194,7 @@
 
     void updateUrlIcon() {
         if (mUrlInput.hasFocus()) {
-            mUrlIcon.setImageResource(R.drawable.ic_search_holo_dark);
+            mUrlIcon.setImageResource(R.drawable.ic_action_search_normal);
         } else {
             if (mFaviconDrawable == null) {
                 mFaviconDrawable = mBaseUi.getFaviconDrawable(null);
@@ -223,7 +212,7 @@
             }
             mSearchButton.setVisibility(View.GONE);
             mStar.setVisibility(View.GONE);
-            mUrlIcon.setImageResource(R.drawable.ic_search_holo_dark);
+            mUrlIcon.setImageResource(R.drawable.ic_action_search_normal);
         } else {
             if (mHideNavButtons) {
                 showNavButtons();
@@ -232,8 +221,6 @@
             mSearchButton.setVisibility(View.VISIBLE);
             updateUrlIcon();
         }
-        mUrlContainer.setBackgroundDrawable(focus
-                ? mFocusDrawable : mUnfocusDrawable);
     }
 
     private void stopOrRefresh() {
@@ -324,6 +311,7 @@
 
     @Override
     public void onStateChanged(int state) {
+        super.onStateChanged(state);
         mVoiceButton.setVisibility(View.GONE);
         switch(state) {
         case STATE_NORMAL: