Change GLGetProcAddress typedef to function returning function pointer

ui/gl/gl_implementation.cc

 // Copyright (c) 2012 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.
 
 #include "ui/gl/gl_implementation.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <string>
@@ skipping 105 matching lines @@
 
 void UnloadGLNativeLibraries() {
   CleanupNativeLibraries(NULL);
 }
 
 void SetGLGetProcAddressProc(GLGetProcAddressProc proc) {
   DCHECK(proc);
   g_get_proc_address = proc;
 }
 
-void* GetGLProcAddress(const char* name) {
+GLFunctionPointerType GetGLProcAddress(const char* name) {
   DCHECK(g_gl_implementation != kGLImplementationNone);
 
   if (g_libraries) {
     for (size_t i = 0; i < g_libraries->size(); ++i) {
-      void* proc = base::GetFunctionPointerFromNativeLibrary((*g_libraries)[i],
-                                                             name);
+      GLFunctionPointerType proc = reinterpret_cast<GLFunctionPointerType>(
+          base::GetFunctionPointerFromNativeLibrary((*g_libraries)[i], name));
       if (proc)
         return proc;
     }
   }
   if (g_get_proc_address) {
-    void* proc = g_get_proc_address(name);
+    GLFunctionPointerType proc = g_get_proc_address(name);
     if (proc)
       return proc;
   }
 
   return NULL;
 }
 
 void InitializeNullDrawGLBindings() {
   // This is platform independent, so it does not need to live in a platform
   // specific implementation file.
@@ skipping 72 matching lines @@
   base::NativeLibrary library = base::LoadNativeLibrary(filename, &error);
   if (!library) {
     LOG(ERROR) << "Failed to load " << filename.MaybeAsASCII() << ": "
                << error.ToString();
     return NULL;
   }
   return library;
 }
 
 }  // namespace gl