Workaround for Intel 6xxx clear to 0/1 bug

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 ba66b85ddf639241beb3916df95e0cae6acc2418..31f6ceb3e942e40968054b8742b5fd04fdd4d1c4 100644
--- a/ui/gl/gl_gl_api_implementation.h
+++ b/ui/gl/gl_gl_api_implementation.h
@@ -103,6 +103,10 @@ class GL_EXPORT RealGLApi : public GLApiBase {
                                           GLsizei height) override;
 
   void glClearFn(GLbitfield mask) override;
+  void glClearColorFn(GLclampf red,
+                      GLclampf green,
+                      GLclampf blue,
+                      GLclampf alpha) override;
   void glDrawArraysFn(GLenum mode, GLint first, GLsizei count) override;
   void glDrawElementsFn(GLenum mode,
                         GLsizei count,
@@ -113,6 +117,7 @@ class GL_EXPORT RealGLApi : public GLApiBase {
   void glDepthRangeFn(GLclampd z_near, GLclampd z_far) override;
 
   void InitializeFilteredExtensions();
+  void setGLContext(GLContext* context);
   void set_version(std::unique_ptr<GLVersionInfo> version);
 
  private:
@@ -121,6 +126,7 @@ class GL_EXPORT RealGLApi : public GLApiBase {
   std::vector<std::string> filtered_exts_;
   std::string filtered_exts_str_;
 
+  GLContext* gl_context_;
   std::unique_ptr<GLVersionInfo> version_;
 
 #if DCHECK_IS_ON()