Workaround for Intel 6xxx clear to 0/1 bug

ui/gl/gl_context.cc

Index: ui/gl/gl_context.cc
diff --git a/ui/gl/gl_context.cc b/ui/gl/gl_context.cc
index 0f3b3561390189453f9c746bfb31a7a43f564546..5fbe7f1412585fd9ad071b543cc433ae5dacc2b3 100644
--- a/ui/gl/gl_context.cc
+++ b/ui/gl/gl_context.cc
@@ -210,6 +210,14 @@ void GLContext::SetCurrent(GLSurface* surface) {
   }
 }
 
+GLWorkarounds GLContext::GetGLWorkarounds() {
+  return gl_workarounds_;
+}
+
+void GLContext::SetGLWorkarounds(const GLWorkarounds& workarounds) {
+  gl_workarounds_ = workarounds;
+}
+
 GLStateRestorer* GLContext::GetGLStateRestorer() {
   return state_restorer_.get();
 }
@@ -243,6 +251,7 @@ void GLContext::InitializeDynamicBindings() {
     if (real_gl_api_) {
       real_gl_api_->InitializeFilteredExtensions();
       real_gl_api_->set_version(GenerateGLVersionInfo());
+      real_gl_api_->setGLContext(this);

[Zhenyao Mo, 2017/06/26 21:45:22]

This is less optimal.  GLContext owns real_gl_api_, so you can easily pass
GLWorkaround to real_gl_api_ without creating this back link.

For example, in SetGLWorkarounds, you can just pass it to real_gl_api_.  If
real_gl_api_ is null at the time (please double check the life cycle and order
of things), then you can do it in GLContext::CreateGLApi()

[jiajia.qin, 2017/06/28 10:03:38]

Sorry for so many iterations. Please check the newest patch which will pass the
GLWorkarounds to RealGLApi. Beside that, patch set 9 is also a workable method.
Both are per-context and set GLWorkarounds by GLContext. The main differ is one
has GLWorkaround as a member of RealGLApi, another has GLWorkaround outside of
RealGLApi but in gl_gl_api_implementation.cc. If you think patch set 9 is more
simple, I can re-back to it. Thanks.

     }
 
     driver_gl_->InitializeDynamicBindings(GetVersionInfo(), GetExtensions());