Revert "Adapt TextLayoutCache for new Harfbuzz scripts"

This reverts commit 7f4ae758ba

This CL created a regression:

#5134317 Arabic Keyboard does not appear

core/jni/Android.mk

@@ -178,7 +178,6 @@ LOCAL_C_INCLUDES += \
 	external/icu4c/i18n \
 	external/icu4c/common \
 	external/jpeg \
-	external/harfbuzz/contrib \
 	external/harfbuzz/src \
 	external/zlib \
 	frameworks/opt/emoji \

core/jni/android/graphics/TextLayoutCache.cpp

@@ -17,10 +17,6 @@
 #include "TextLayoutCache.h"
 #include "TextLayout.h"
 
-extern "C" {
-#include "harfbuzz-unicode.h"
-}
-
 namespace android {
 
 TextLayoutCache::TextLayoutCache() :
@@ -359,9 +355,7 @@ void TextLayoutCacheValue::setupShaperItem(HB_ShaperItem* shaperItem, HB_FontRec
     shaperItem->item.pos = start;
     shaperItem->item.length = count;
     shaperItem->item.bidiLevel = isRTL;
-
-    ssize_t iter = 0;
-    shaperItem->item.script = code_point_to_script(utf16_to_code_point(chars, count, &iter));
+    shaperItem->item.script = isRTL ? HB_Script_Arabic : HB_Script_Common;
 
     shaperItem->string = chars;
     shaperItem->stringLength = contextCount;