Declare dependency on blink_headers in targets that use blink headers

ppapi/ppapi_proxy_nacl.gyp

Index: ppapi/ppapi_proxy_nacl.gyp
diff --git a/ppapi/ppapi_proxy_nacl.gyp b/ppapi/ppapi_proxy_nacl.gyp
index bbbab0903d9dac817bce02efea213ea51469dd31..14deb4ca7e9c5cd2d955f2966c4e499239ed3644 100644
--- a/ppapi/ppapi_proxy_nacl.gyp
+++ b/ppapi/ppapi_proxy_nacl.gyp
@@ -28,19 +28,20 @@
             '..',
           ],
           'dependencies': [
-            '../native_client/tools.gyp:prep_toolchain',
             '../base/base_nacl.gyp:base_nacl',
+            '../components/tracing_nacl.gyp:tracing_nacl',
             '../gpu/command_buffer/command_buffer_nacl.gyp:gles2_utils_nacl',
             '../gpu/gpu_nacl.gyp:command_buffer_client_nacl',
             '../gpu/gpu_nacl.gyp:command_buffer_common_nacl',
-            '../gpu/gpu_nacl.gyp:gles2_implementation_nacl',
             '../gpu/gpu_nacl.gyp:gles2_cmd_helper_nacl',
+            '../gpu/gpu_nacl.gyp:gles2_implementation_nacl',
             '../gpu/gpu_nacl.gyp:gpu_ipc_nacl',
             '../ipc/ipc_nacl.gyp:ipc_nacl',
-            '../ppapi/ppapi_shared_nacl.gyp:ppapi_shared_nacl',
+            '../native_client/tools.gyp:prep_toolchain',
             '../ppapi/ppapi_ipc_nacl.gyp:ppapi_ipc_nacl',
+            '../ppapi/ppapi_shared_nacl.gyp:ppapi_shared_nacl',
+            '../third_party/WebKit/public/blink_headers.gyp:blink_headers',
             '../third_party/khronos/khronos.gyp:khronos_headers',
-            '../components/tracing_nacl.gyp:tracing_nacl',
           ],
         },
       ],