Build fontchain_lint using python_binary_host

Test: out/host/linux-x86/bin/fontchain_lint
out/target/product/generic/system true external/unicode
Bug: b/27727331

Change-Id: Ib9353d2338c3b939027069f49e3e847c65526581

Android.bp

@@ -102,3 +102,29 @@ java_library {
     dxflags: ["--core-library"],
     installable: false,
 }
+
+python_defaults {
+    name: "base_default",
+    version: {
+        py2: {
+            enabled: true,
+            embedded_launcher: true,
+        },
+        py3: {
+            enabled: false,
+            embedded_launcher: false,
+        },
+    },
+}
+
+python_binary_host {
+    name: "fontchain_linter",
+    defaults: ["base_default"],
+    main: "tools/fonts/fontchain_linter.py",
+    srcs: [
+        "tools/fonts/fontchain_linter.py",
+    ],
+    libs: [
+        "fontTools",
+    ],
+}

data/fonts/Android.mk

@@ -112,7 +112,7 @@ include $(BUILD_PREBUILT)
 # Run sanity tests on fonts on checkbuild
 checkbuild: fontchain_lint
 
-FONTCHAIN_LINTER := frameworks/base/tools/fonts/fontchain_lint.py
+FONTCHAIN_LINTER := $(HOST_OUT_EXECUTABLES)/fontchain_linter
 ifeq ($(MINIMAL_FONT_FOOTPRINT),true)
 CHECK_EMOJI := false
 else
@@ -121,5 +121,4 @@ endif
 
 .PHONY: fontchain_lint
 fontchain_lint: $(FONTCHAIN_LINTER) $(TARGET_OUT)/etc/fonts.xml $(PRODUCT_OUT)/system.img
-	PYTHONPATH=$$PYTHONPATH:external/fonttools/Lib \
-	python $(FONTCHAIN_LINTER) $(TARGET_OUT) $(CHECK_EMOJI) external/unicode
+	$(FONTCHAIN_LINTER) $(TARGET_OUT) $(CHECK_EMOJI) external/unicode