Split interface and jni java target

Summary:
Split the yoga buck targets from interface to actual implementation.

This is currently done without moving any files folder, since only we will make the distinction between interface<-->implementation only this buck target (and not in the litho/reactnative yoga copies).

Buck does insures that the `java-interface` is pure since it doesn't depend on any fbjni code.

Reviewed By: SidharthGuglani

Differential Revision: D17266406

fbshipit-source-id: 46aa469b74c2c3114f1d3d762c41d32cfe269f57

java/BUCK

@@ -10,6 +10,12 @@ CXX_LIBRARY_WHITELIST_FOR_TESTS = CXX_LIBRARY_WHITELIST + [
     yoga_cxx_lib("testutil:testutil"),
 ]
 
+YOGA_JAVA_IMPLEMENTATION_FILES = [
+    "com/facebook/yoga/*JNI*.java",
+    "com/facebook/yoga/*Factory.java",
+    "com/facebook/yoga/YogaNative.java",
+]
+
 yoga_cxx_library(
     name = "jni",
     srcs = glob(["jni/*.cpp"]),
@@ -38,9 +44,40 @@ yoga_cxx_library(
     ],
 )
 
+yoga_java_library(
+    name = "java-interface",
+    srcs = glob(
+        ["com/facebook/yoga/*.java"],
+        exclude = YOGA_JAVA_IMPLEMENTATION_FILES,
+    ),
+    required_for_source_only_abi = True,
+    source = "1.7",
+    target = "1.7",
+    visibility = ["PUBLIC"],
+    deps = [
+        JSR_305_TARGET,
+        PROGRUARD_ANNOTATIONS_TARGET,
+    ],
+)
+
+yoga_java_library(
+    name = "java-impl",
+    srcs = glob(YOGA_JAVA_IMPLEMENTATION_FILES),
+    required_for_source_only_abi = True,
+    source = "1.7",
+    target = "1.7",
+    deps = [
+        ":java-interface",
+        ":jni",
+        FBJNI_JAVA_TARGET,
+        JSR_305_TARGET,
+        PROGRUARD_ANNOTATIONS_TARGET,
+        SOLOADER_TARGET,
+    ],
+)
+
 yoga_java_library(
     name = "java",
-    srcs = glob(["com/facebook/yoga/*.java"]),
     required_for_source_only_abi = True,
     source = "1.7",
     target = "1.7",
@@ -48,12 +85,9 @@ yoga_java_library(
         yoga_dep("java:tests"),
     ],
     visibility = ["PUBLIC"],
-    deps = [
-        ":jni",
-        FBJNI_JAVA_TARGET,
-        JSR_305_TARGET,
-        PROGRUARD_ANNOTATIONS_TARGET,
-        SOLOADER_TARGET,
+    exported_deps = [
+        ":java-impl",
+        ":java-interface",
     ],
 )