Take GL version and extensions correctly into account when binding functions

ui/gl/gl_context.h

Index: ui/gl/gl_context.h
diff --git a/ui/gl/gl_context.h b/ui/gl/gl_context.h
index 3eb390fce5cb03f4dcca9e43cc2eda7d12f35f93..66a763167ba67ca2e505a100b4b863aa0b94b04c 100644
--- a/ui/gl/gl_context.h
+++ b/ui/gl/gl_context.h
@@ -18,6 +18,7 @@ namespace gfx {
 
 class GLSurface;
 class VirtualGLApi;
+struct GLVersionInfo;
 
 // Encapsulates an OpenGL context, hiding platform specific management.
 class GL_EXPORT GLContext : public base::RefCounted<GLContext> {
@@ -76,6 +77,10 @@ class GL_EXPORT GLContext : public base::RefCounted<GLContext> {
   // context must be current.
   bool HasExtension(const char* name);
 
+  // Returns version info of the underlying GL context. The context must be
+  // current.
+  const GLVersionInfo* GetVersionInfo();
+
   GLShareGroup* share_group();
 
   // Create a GL context that is compatible with the given surface.
@@ -110,14 +115,17 @@ class GL_EXPORT GLContext : public base::RefCounted<GLContext> {
   static void SetRealGLApi();
   virtual void SetCurrent(GLSurface* surface);
 
-  // Initialize function pointers to extension functions in the GL
-  // implementation. Should be called immediately after this context is made
-  // current.
-  bool InitializeExtensionBindings();
+  // Initialize function pointers to functions where the bound version depends
+  // on GL version or supported extensions. Should be called immediately after
+  // this context is made current.
+  bool InitializeDynamicBindings();
 
   // Returns the last real (non-virtual) GLContext made current.
   static GLContext* GetRealCurrent();
 
+  // Returns the GL version string. The context must be current.
+  virtual std::string GetGLVersion();
+
  private:
   friend class base::RefCounted<GLContext>;
 
@@ -127,6 +135,7 @@ class GL_EXPORT GLContext : public base::RefCounted<GLContext> {
   scoped_refptr<GLShareGroup> share_group_;
   scoped_ptr<VirtualGLApi> virtual_gl_api_;
   scoped_ptr<GLStateRestorer> state_restorer_;
+  scoped_ptr<GLVersionInfo> version_info_;
 
   DISALLOW_COPY_AND_ASSIGN(GLContext);
 };