Revert 247793 "Ensure GL initialization only happens once, and p..."

trunk/src/ui/gl/gl_gl_api_implementation.cc

Index: trunk/src/ui/gl/gl_gl_api_implementation.cc
===================================================================
--- trunk/src/ui/gl/gl_gl_api_implementation.cc	(revision 247809)
+++ trunk/src/ui/gl/gl_gl_api_implementation.cc	(working copy)
@@ -146,35 +146,18 @@
 
 }  // anonymous namespace
 
-DriverGL::DriverGL() { ClearBindings(); }
-
 void DriverGL::InitializeCustomDynamicBindings(GLContext* context) {
   InitializeDynamicBindings(context);
-
-  DCHECK(orig_fn.glTexImage2DFn == NULL);
-  orig_fn.glTexImage2DFn = fn.glTexImage2DFn;
+  orig_fn = fn;
   fn.glTexImage2DFn =
       reinterpret_cast<glTexImage2DProc>(CustomTexImage2D);
-
-  DCHECK(orig_fn.glTexSubImage2DFn == NULL);
-  orig_fn.glTexSubImage2DFn = fn.glTexSubImage2DFn;
   fn.glTexSubImage2DFn =
       reinterpret_cast<glTexSubImage2DProc>(CustomTexSubImage2D);
-
-  DCHECK(orig_fn.glTexStorage2DEXTFn == NULL);
-  orig_fn.glTexStorage2DEXTFn = fn.glTexStorage2DEXTFn;
   fn.glTexStorage2DEXTFn =
       reinterpret_cast<glTexStorage2DEXTProc>(CustomTexStorage2DEXT);
-
-  DCHECK(orig_fn.glRenderbufferStorageEXTFn == NULL);
-  orig_fn.glRenderbufferStorageEXTFn = fn.glRenderbufferStorageEXTFn;
   fn.glRenderbufferStorageEXTFn =
       reinterpret_cast<glRenderbufferStorageEXTProc>(
       CustomRenderbufferStorageEXT);
-
-  DCHECK(orig_fn.glRenderbufferStorageMultisampleEXTFn == NULL);
-  orig_fn.glRenderbufferStorageMultisampleEXTFn =
-      fn.glRenderbufferStorageMultisampleEXTFn;
   fn.glRenderbufferStorageMultisampleEXTFn =
       reinterpret_cast<glRenderbufferStorageMultisampleEXTProc>(
       CustomRenderbufferStorageMultisampleEXT);