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();

[no sievers, 2013/12/05 20:51:57]

Is a call to this missing in GLContextNSView::MakeCurrent()?

[no sievers, 2013/12/05 21:07:17]

I also suggest that we initialize the dynamic bindings more explicitly since
doing it this way in GLContext is just flaky. In gpu_main.cc and
gpu_child_thread.cc we already make a context current for most cases (see
gpu_main.cc and CollectContextGraphicsInfo(), and for Windows we actually need
the context current already for binding core functions, it seems). We could
maybe also do it in GpuChildThread::OnInitialize().

It has nothing to do with your patch directly though and we can do it as a
follow-up.

[oetuaho, 2013/12/09 17:17:07]

Yeah, after seeing the gpu_main.cc code it looks like the context could just
always be initialized from there after minimal bindings needed for that are
done, so some of this complexity would be avoided.

You're right about the GLContextNSView, it looks like a call needs to be added.

 
   // 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);
 };