[Reland] Mojo: Eliminate duplicate C API symbols

mojo/public/c/system/thunks.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // 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_
+#ifndef MOJO_PUBLIC_C_SYSTEM_THUNKS_H_
+#define MOJO_PUBLIC_C_SYSTEM_THUNKS_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "mojo/public/c/system/core.h"
+#include "mojo/public/c/system/system_export.h"
 
 // The embedder needs to bind the basic Mojo Core functions of a DSO to those of
 // the embedder when loading a DSO that is dependent on mojo_system.
 // The typical usage would look like:
 // base::ScopedNativeLibrary app_library(
 //     base::LoadNativeLibrary(app_path_, &error));
 // typedef MojoResult (*MojoSetSystemThunksFn)(MojoSystemThunks*);
 // MojoSetSystemThunksFn mojo_set_system_thunks_fn =
 //     reinterpret_cast<MojoSetSystemThunksFn>(app_library.GetFunctionPointer(
 //         "MojoSetSystemThunks"));
@@ skipping 124 matching lines @@
       MojoPlatformSharedBufferHandleFlags flags,
       MojoHandle* mojo_handle);
   MojoResult (*UnwrapPlatformSharedBufferHandle)(
       MojoHandle mojo_handle,
       struct MojoPlatformHandle* platform_handle,
       size_t* num_bytes,
       MojoPlatformSharedBufferHandleFlags* flags);
 };
 #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() {
-  MojoSystemThunks system_thunks = {sizeof(MojoSystemThunks),
-                                    MojoGetTimeTicksNow,
-                                    MojoClose,
-                                    MojoWait,
-                                    MojoWaitMany,
-                                    MojoCreateMessagePipe,
-                                    MojoWriteMessage,
-                                    MojoReadMessage,
-                                    MojoCreateDataPipe,
-                                    MojoWriteData,
-                                    MojoBeginWriteData,
-                                    MojoEndWriteData,
-                                    MojoReadData,
-                                    MojoBeginReadData,
-                                    MojoEndReadData,
-                                    MojoCreateSharedBuffer,
-                                    MojoDuplicateBufferHandle,
-                                    MojoMapBuffer,
-                                    MojoUnmapBuffer,
-                                    MojoCreateWaitSet,
-                                    MojoAddHandle,
-                                    MojoRemoveHandle,
-                                    MojoGetReadyHandles,
-                                    MojoWatch,
-                                    MojoCancelWatch,
-                                    MojoFuseMessagePipes,
-                                    MojoWriteMessageNew,
-                                    MojoReadMessageNew,
-                                    MojoAllocMessage,
-                                    MojoFreeMessage,
-                                    MojoGetMessageBuffer,
-                                    MojoWrapPlatformHandle,
-                                    MojoUnwrapPlatformHandle,
-                                    MojoWrapPlatformSharedBufferHandle,
-                                    MojoUnwrapPlatformSharedBufferHandle};
-  return system_thunks;
-}
-#endif
-
-
 // Use this type for the function found by dynamically discovering it in
 // a DSO linked with mojo_system. For example:
 // MojoSetSystemThunksFn mojo_set_system_thunks_fn =
 //     reinterpret_cast<MojoSetSystemThunksFn>(app_library.GetFunctionPointer(
 //         "MojoSetSystemThunks"));
-// The expected size of |system_thunks} is returned.
+// The expected size of |system_thunks| is returned.
 // The contents of |system_thunks| are copied.
 typedef size_t (*MojoSetSystemThunksFn)(
     const struct MojoSystemThunks* system_thunks);
 
-#endif  // MOJO_PUBLIC_PLATFORM_NATIVE_SYSTEM_THUNKS_H_
+// A function for setting up the embedder's own system thunks. This should only
+// be called by Mojo embedder code.
+MOJO_SYSTEM_EXPORT size_t MojoEmbedderSetSystemThunks(
+    const struct MojoSystemThunks* system_thunks);
+
+#endif  // MOJO_PUBLIC_C_SYSTEM_THUNKS_H_