Take GL version and extensions correctly into account when binding functions

ui/gl/gl_implementation.h

 // 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.
 
 #ifndef UI_GL_GL_IMPLEMENTATION_H_
 #define UI_GL_GL_IMPLEMENTATION_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 24 matching lines @@
 
 void GetAllowedGLImplementations(std::vector<GLImplementation>* impls);
 
 #if defined(OS_WIN)
 typedef void* (WINAPI *GLGetProcAddressProc)(const char* name);
 #else
 typedef void* (*GLGetProcAddressProc)(const char* name);
 #endif
 
 // Initialize a particular GL implementation.
-GL_EXPORT bool InitializeGLBindings(GLImplementation implementation);
+GL_EXPORT bool InitializeStaticGLBindings(GLImplementation implementation);
 
-// Initialize extension function bindings for a GL implementation.
-GL_EXPORT bool InitializeGLExtensionBindings(GLImplementation implementation,
+// Initialize function bindings that depend on the context for a GL
+// implementation.
+GL_EXPORT bool InitializeDynamicGLBindings(GLImplementation implementation,
     GLContext* context);
 
 // Initialize Debug logging wrappers for GL bindings.
 void InitializeDebugGLBindings();
 
 GL_EXPORT void ClearGLBindings();
 
 // Set the current GL implementation.
 GL_EXPORT void SetGLImplementation(GLImplementation implementation);
 
@@ skipping 12 matching lines @@
 
 // Add a native library to those searched for GL entry points.
 void AddGLNativeLibrary(base::NativeLibrary library);
 
 // Unloads all native libraries.
 void UnloadGLNativeLibraries();
 
 // Set an additional function that will be called to find GL entry points.
 void SetGLGetProcAddressProc(GLGetProcAddressProc proc);
 
-// Find a core (non-extension) entry point in the current GL implementation. On
-// EGL based implementations core entry points will not be queried through
-// GLGetProcAddressProc.
-void* GetGLCoreProcAddress(const char* name);
-
-// Find an entry point in the current GL implementation.
+// Find an entry point in the current GL implementation. Note that the function
+// may return garbage if an unsupported function is queried. This is the case at
+// least with spec-compliant eglGetProcAddress and glxGetProcAddress and when
+// querying functions from the EGL library supplied by Android, which contains
+// stubs for unsupported functions known to that Android version.
 void* GetGLProcAddress(const char* name);
 
 // Return information about the GL window system binding implementation (e.g.,
 // EGL, GLX, WGL). Returns true if the information was retrieved successfully.
 GL_EXPORT bool GetGLWindowSystemBindingInfo(GLWindowSystemBindingInfo* info);
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_IMPLEMENTATION_H_