Refactor GL bindings so there is no global GLApi or DriverGL.

ui/gl/gl_bindings.h

Index: ui/gl/gl_bindings.h
diff --git a/ui/gl/gl_bindings.h b/ui/gl/gl_bindings.h
index 322b2c2b7524d2eccaf92f6b3b298588e13eee6c..3ea6199b175255a3abb5b2d54a5ebe45a77c5e42 100644
--- a/ui/gl/gl_bindings.h
+++ b/ui/gl/gl_bindings.h
@@ -397,34 +397,30 @@ typedef uint64_t EGLuint64CHROMIUM;
 
 namespace gl {
 
+struct GLVersionInfo;
+
 struct GL_EXPORT DriverGL {
   void InitializeStaticBindings();
-  void InitializeCustomDynamicBindings(GLContext* context);
-  void InitializeDebugBindings();
-  void InitializeNullDrawBindings();
-  // TODO(danakj): Remove this when all test suites are using null-draw.
-  bool HasInitializedNullDrawBindings();
-  bool SetNullDrawBindingsEnabled(bool enabled);
+  void InitializeDynamicBindings(const GLVersionInfo* ver,
+                                 const std::string& context_extensions);
   void ClearBindings();
 
   ProcsGL fn;
-  ProcsGL orig_fn;
-  ProcsGL debug_fn;
   ExtensionsGL ext;
-  bool null_draw_bindings_enabled;
+};
 
- private:
-  void InitializeDynamicBindings(GLContext* context);
+struct GL_EXPORT CurrentGL {
+  GLApi* Api = nullptr;
+  DriverGL* Driver = nullptr;
+  const GLVersionInfo* Version = nullptr;
 };
 
 struct GL_EXPORT DriverOSMESA {
   void InitializeStaticBindings();
   void InitializeExtensionBindings();
-  void InitializeDebugBindings();
   void ClearBindings();
 
   ProcsOSMESA fn;
-  ProcsOSMESA debug_fn;
   ExtensionsOSMESA ext;
 
  private:
@@ -435,11 +431,9 @@ struct GL_EXPORT DriverOSMESA {
 struct GL_EXPORT DriverWGL {
   void InitializeStaticBindings();
   void InitializeExtensionBindings();
-  void InitializeDebugBindings();
   void ClearBindings();
 
   ProcsWGL fn;
-  ProcsWGL debug_fn;
   ExtensionsWGL ext;
 
  private:
@@ -452,11 +446,9 @@ struct GL_EXPORT DriverEGL {
   void InitializeStaticBindings();
   void InitializeClientExtensionBindings();
   void InitializeExtensionBindings();
-  void InitializeDebugBindings();
   void ClearBindings();
 
   ProcsEGL fn;
-  ProcsEGL debug_fn;
   ExtensionsEGL ext;
 
   static std::string GetPlatformExtensions();
@@ -468,11 +460,9 @@ struct GL_EXPORT DriverEGL {
 struct GL_EXPORT DriverGLX {
   void InitializeStaticBindings();
   void InitializeExtensionBindings();
-  void InitializeDebugBindings();
   void ClearBindings();
 
   ProcsGLX fn;
-  ProcsGLX debug_fn;
   ExtensionsGLX ext;
 
  private:
@@ -481,11 +471,12 @@ struct GL_EXPORT DriverGLX {
 #endif
 
 // This #define is here to support autogenerated code.
-#define g_current_gl_context g_current_gl_context_tls->Get()
-GL_EXPORT extern base::ThreadLocalPointer<GLApi>* g_current_gl_context_tls;
+#define g_current_gl_context g_current_gl_context_tls->Get()->Api
+#define g_current_gl_driver g_current_gl_context_tls->Get()->Driver
+#define g_current_gl_version g_current_gl_context_tls->Get()->Version
+GL_EXPORT extern base::ThreadLocalPointer<CurrentGL>* g_current_gl_context_tls;
 
 GL_EXPORT extern OSMESAApi* g_current_osmesa_context;
-GL_EXPORT extern DriverGL g_driver_gl;
 GL_EXPORT extern DriverOSMESA g_driver_osmesa;
 
 #if defined(USE_EGL)