Change GLGetProcAddress typedef to function returning function pointer

ui/gl/glx_api_unittest.cc

Index: ui/gl/glx_api_unittest.cc
diff --git a/ui/gl/glx_api_unittest.cc b/ui/gl/glx_api_unittest.cc
index 16f50f4af874e1be2c32079878dc5ec1bd409950..c36c725922823e2fb3ca0da5c27399ca0ebd08cf 100644
--- a/ui/gl/glx_api_unittest.cc
+++ b/ui/gl/glx_api_unittest.cc
@@ -57,9 +57,11 @@ class GLXApiTest : public testing::Test {
     return static_cast<GLXContext>(nullptr);
   }
 
-  static void* GL_BINDING_CALL FakeGLGetProcAddress(const char *proc) {
+  static GLFunctionPointerType GL_BINDING_CALL
+  FakeGLGetProcAddress(const char* proc) {
     if (!strcmp("glXCreateContextAttribsARB", proc)) {
-      return reinterpret_cast<void *>(&FakeCreateContextAttribsARB);
+      return reinterpret_cast<GLFunctionPointerType>(
+          &FakeCreateContextAttribsARB);
     }
     return NULL;
   }