Source release 15.2.0

third_party/protoc.gypi

@@ -3,6 +3,7 @@
   'variables': {
     'cc_dir': '<(SHARED_INTERMEDIATE_DIR)/protoc_out',
     'proto_in_dir%': '.',
+    'protoc_gyp%': '',
   },
   'conditions': [
     ['protobuf_config=="system"', {
@@ -28,11 +29,11 @@
       # protobuf_lib is a source folder.
       # We use the targets in protobuf.gypi.
       'dependencies': [
-        'protoc#host',
-        'protobuf_lite',
+        '<(protoc_gyp):protoc#host',
+        '<(protoc_gyp):protobuf_lite',
       ],
       'export_dependent_settings': [
-        'protobuf_lite',
+        '<(protoc_gyp):protobuf_lite',
       ],
       'variables': {
         # Since we are building our own protoc, override protoc_bin.