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

ui/gl/gl_osmesa_api_implementation.h

Index: ui/gl/gl_osmesa_api_implementation.h
diff --git a/ui/gl/gl_osmesa_api_implementation.h b/ui/gl/gl_osmesa_api_implementation.h
index 92e5f5acfb819d537c2e731b549cb0a1d256f734..6163b198def40fdce4abd832b42f91bc42158d8c 100644
--- a/ui/gl/gl_osmesa_api_implementation.h
+++ b/ui/gl/gl_osmesa_api_implementation.h
@@ -37,6 +37,21 @@ class GL_EXPORT RealOSMESAApi : public OSMESAApiBase {
   void Initialize(DriverOSMESA* driver);
 };
 
+// Logs debug information for every OSMESA call.
+class GL_EXPORT DebugOSMESAApi : public OSMESAApi {
+ public:
+  DebugOSMESAApi(OSMESAApi* osmesa_api);
+  ~DebugOSMESAApi() override;
+
+  // Include the auto-generated part of this class. We split this because
+  // it means we can easily edit the non-auto generated parts right here in
+  // this file instead of having to edit some template or the code generator.
+  #include "gl_bindings_api_autogen_osmesa.h"
+
+ private:
+  OSMESAApi* osmesa_api_;
+};
+
 // Inserts a TRACE for every OSMESA call.
 class GL_EXPORT TraceOSMESAApi : public OSMESAApi {
  public: