Extract color for the hotseat.

- Only considers the bottom fourth of the wallpaper
- Is translucent black or white depending on how dark/light
  the wallpaper is
- Hotseat extends behind the nav bar

Bug: 27230217
Change-Id: Id4ea6ee91b4dd221b4c277d22d5041cab178801d
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 21adcb7..2a83299 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -496,9 +496,10 @@
     }
 
     private void loadExtractedColorsAndColorItems() {
-        if (mExtractedColors != null) {
+        // TODO: do this in pre-N as well, once the extraction part is complete.
+        if (mExtractedColors != null && Utilities.isNycOrAbove()) {
             mExtractedColors.load(this);
-            // TODO: pass mExtractedColors to interested items such as hotseat.
+            mHotseat.updateColor(mExtractedColors, !mPaused);
         }
     }