Take GL version and extensions correctly into account when binding functions

ui/gl/gl_implementation.h

Index: ui/gl/gl_implementation.h
diff --git a/ui/gl/gl_implementation.h b/ui/gl/gl_implementation.h
index 212978270d6f13a38e36429daac67bd2521f05ca..7d36b432e8a72a2e3a41fc0c5d2d6bfcb03552c5 100644
--- a/ui/gl/gl_implementation.h
+++ b/ui/gl/gl_implementation.h
@@ -42,10 +42,11 @@ 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.
@@ -78,12 +79,11 @@ 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.,