Adapt TextLayoutCache for new Harfbuzz scripts

The Harfbuzz script setting was wired to HB_Script_Common for left-
to-right text and HB_Script_Arabic for right-to-left. This change
selects from additional scripts using some utility APIs from
Harfbuzz.

Change-Id: I34a6f1e0407c8d122bc968443948e7863d1f91ed
diff --git a/core/jni/Android.mk b/core/jni/Android.mk
index 6e73889..170957c 100644
--- a/core/jni/Android.mk
+++ b/core/jni/Android.mk
@@ -178,6 +178,7 @@
 	external/icu4c/i18n \
 	external/icu4c/common \
 	external/jpeg \
+	external/harfbuzz/contrib \
 	external/harfbuzz/src \
 	external/zlib \
 	frameworks/opt/emoji \
diff --git a/core/jni/android/graphics/TextLayoutCache.cpp b/core/jni/android/graphics/TextLayoutCache.cpp
index 30fe298..a29eb38 100644
--- a/core/jni/android/graphics/TextLayoutCache.cpp
+++ b/core/jni/android/graphics/TextLayoutCache.cpp
@@ -17,6 +17,10 @@
 #include "TextLayoutCache.h"
 #include "TextLayout.h"
 
+extern "C" {
+#include "harfbuzz-unicode.h"
+}
+
 namespace android {
 
 TextLayoutCache::TextLayoutCache() :
@@ -355,7 +359,9 @@
     shaperItem->item.pos = start;
     shaperItem->item.length = count;
     shaperItem->item.bidiLevel = isRTL;
-    shaperItem->item.script = isRTL ? HB_Script_Arabic : HB_Script_Common;
+
+    ssize_t iter = 0;
+    shaperItem->item.script = code_point_to_script(utf16_to_code_point(chars, count, &iter));
 
     shaperItem->string = chars;
     shaperItem->stringLength = contextCount;