Add Go build support for GN.

mojo/public/platform/native/system_thunks.h

Index: mojo/public/platform/native/system_thunks.h
diff --git a/mojo/public/platform/native/system_thunks.h b/mojo/public/platform/native/system_thunks.h
index de82eba1bfc1e7adedb30737f1c575e0de8c13c0..d53485c360769954ae8fa7d3f9f0cb7d7533a149 100644
--- a/mojo/public/platform/native/system_thunks.h
+++ b/mojo/public/platform/native/system_thunks.h
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// Note: This header should be compilable as C.
+
 #ifndef MOJO_PUBLIC_PLATFORM_NATIVE_SYSTEM_THUNKS_H_
 #define MOJO_PUBLIC_PLATFORM_NATIVE_SYSTEM_THUNKS_H_
 
@@ -43,9 +45,10 @@ struct MojoSystemThunks {
                          const MojoHandleSignals* signals,
                          uint32_t num_handles,
                          MojoDeadline deadline);
-  MojoResult (*CreateMessagePipe)(const MojoCreateMessagePipeOptions* options,
-                                  MojoHandle* message_pipe_handle0,
-                                  MojoHandle* message_pipe_handle1);
+  MojoResult (*CreateMessagePipe)(
+      const struct MojoCreateMessagePipeOptions* options,
+      MojoHandle* message_pipe_handle0,
+      MojoHandle* message_pipe_handle1);
   MojoResult (*WriteMessage)(MojoHandle message_pipe_handle,
                              const void* bytes,
                              uint32_t num_bytes,
@@ -58,7 +61,7 @@ struct MojoSystemThunks {
                             MojoHandle* handles,
                             uint32_t* num_handles,
                             MojoReadMessageFlags flags);
-  MojoResult (*CreateDataPipe)(const MojoCreateDataPipeOptions* options,
+  MojoResult (*CreateDataPipe)(const struct MojoCreateDataPipeOptions* options,
                                MojoHandle* data_pipe_producer_handle,
                                MojoHandle* data_pipe_consumer_handle);
   MojoResult (*WriteData)(MojoHandle data_pipe_producer_handle,
@@ -82,12 +85,12 @@ struct MojoSystemThunks {
   MojoResult (*EndReadData)(MojoHandle data_pipe_consumer_handle,
                             uint32_t num_elements_read);
   MojoResult (*CreateSharedBuffer)(
-      const MojoCreateSharedBufferOptions* options,
+      const struct MojoCreateSharedBufferOptions* options,
       uint64_t num_bytes,
       MojoHandle* shared_buffer_handle);
   MojoResult (*DuplicateBufferHandle)(
       MojoHandle buffer_handle,
-      const MojoDuplicateBufferHandleOptions* options,
+      const struct MojoDuplicateBufferHandleOptions* options,
       MojoHandle* new_buffer_handle);
   MojoResult (*MapBuffer)(MojoHandle buffer_handle,
                           uint64_t offset,
@@ -98,6 +101,8 @@ struct MojoSystemThunks {
 };
 #pragma pack(pop)
 
+
+#ifdef __cplusplus
 // Intended to be called from the embedder. Returns a |MojoCore| initialized
 // to contain pointers to each of the embedder's MojoCore functions.
 inline MojoSystemThunks MojoMakeSystemThunks() {
@@ -124,6 +129,8 @@ inline MojoSystemThunks MojoMakeSystemThunks() {
   };
   return system_thunks;
 }
+#endif
+
 
 // Use this type for the function found by dynamically discovering it in
 // a DSO linked with mojo_system. For example:
@@ -132,6 +139,7 @@ inline MojoSystemThunks MojoMakeSystemThunks() {
 //         "MojoSetSystemThunks"));
 // The expected size of |system_thunks} is returned.
 // The contents of |system_thunks| are copied.
-typedef size_t (*MojoSetSystemThunksFn)(const MojoSystemThunks* system_thunks);
+typedef size_t (*MojoSetSystemThunksFn)(
+    const struct MojoSystemThunks* system_thunks);
 
 #endif  // MOJO_PUBLIC_PLATFORM_NATIVE_SYSTEM_THUNKS_H_