Separate functional key background from normal one

This CL also moves spacebarBackground attribute from MainKeyboardView
to KeyboardView.

This CL must be checked in together with I48c383ca97.

Bug: 14419121
Change-Id: Id356d0086a8fb21375fb5c66076873258fb3d63e
diff --git a/java/res/values/attrs.xml b/java/res/values/attrs.xml
index 769a1d9..79cc139 100644
--- a/java/res/values/attrs.xml
+++ b/java/res/values/attrs.xml
@@ -41,13 +41,16 @@
     </declare-styleable>
 
     <declare-styleable name="KeyboardView">
-        <!-- Image for the key. This image needs to be a {@link StateListDrawable}, with the
-             following possible states: normal, pressed, checkable, checkable+pressed,
+        <!-- Background image for the key. This image needs to be a {@link StateListDrawable},
+             with the following possible states: normal, pressed, checkable, checkable+pressed,
              checkable+checked, checkable+checked+pressed. -->
         <attr name="keyBackground" format="reference" />
-        <!-- Image for the functional key used in Emoji layout. -->
-        <attr name="keyBackgroundEmojiFunctional" format="reference" />
-
+        <!-- Background image for the functional key. This image needs to be a
+             {@link StateListDrawable}, with the following possible states: normal, pressed. -->
+        <attr name="functionalKeyBackground" format="reference" />
+        <!-- Background image for the spacebar.  This image needs to be a
+             {@link StateListDrawable}, with the following possible states: normal, pressed. -->
+        <attr name="spacebarBackground" format="reference" />
         <!-- Horizontal padding of left/right aligned key label to the edge of the key. -->
         <attr name="keyLabelHorizontalPadding" format="dimension" />
         <!-- Right padding of hint letter to the edge of the key.-->
@@ -76,8 +79,6 @@
         <attr name="languageOnSpacebarTextColor" format="color" />
         <attr name="languageOnSpacebarTextShadowRadius" format="float" />
         <attr name="languageOnSpacebarTextShadowColor" format="color" />
-        <!-- Background image for the spacebar. -->
-        <attr name="spacebarBackground" format="reference" />
         <!-- Fadeout animator for spacebar language label. -->
         <attr name="languageOnSpacebarFinalAlpha" format="integer" />
         <attr name="languageOnSpacebarFadeoutAnimator" format="reference" />