Fix GL extension filtering so that extension bits are set correctly.

ui/gl/gl_gl_api_implementation.h

Index: ui/gl/gl_gl_api_implementation.h
diff --git a/ui/gl/gl_gl_api_implementation.h b/ui/gl/gl_gl_api_implementation.h
index 35d040c411da216587545ae9feb323f180ee376d..bbf41c96bcf0fcdf0d45d1499fd0cbf882d336f9 100644
--- a/ui/gl/gl_gl_api_implementation.h
+++ b/ui/gl/gl_gl_api_implementation.h
@@ -68,8 +68,9 @@ class GL_EXPORT RealGLApi : public GLApiBase {
   const GLubyte* glGetStringFn(GLenum name) override;
   const GLubyte* glGetStringiFn(GLenum name, GLuint index) override;
 
- private:
   void InitializeFilteredExtensions();
+
+ private:
   void glFinishFn() override;
   void glFlushFn() override;
 
@@ -77,6 +78,10 @@ class GL_EXPORT RealGLApi : public GLApiBase {
   std::vector<std::string> disabled_exts_;
   std::vector<std::string> filtered_exts_;
   std::string filtered_exts_str_;
+
+#if DCHECK_IS_ON()
+  bool filtered_exts_initialized_;
+#endif
 };
 
 // Inserts a TRACE for every GL call.