Make invalidateFramebuffer no-op for DEPTH_STENCIL attachment

gpu/command_buffer/service/renderbuffer_manager.cc

Index: gpu/command_buffer/service/renderbuffer_manager.cc
diff --git a/gpu/command_buffer/service/renderbuffer_manager.cc b/gpu/command_buffer/service/renderbuffer_manager.cc
index 203e74b849d661b1dab15eaa849b41e5069707a9..c9489c8a1742accd40bad7d89ea5f400b02d29c0 100644
--- a/gpu/command_buffer/service/renderbuffer_manager.cc
+++ b/gpu/command_buffer/service/renderbuffer_manager.cc
@@ -111,6 +111,8 @@ Renderbuffer::Renderbuffer(RenderbufferManager* manager,
       client_id_(client_id),
       service_id_(service_id),
       cleared_(true),
+      depth_cleared_(true),
+      stencil_cleared_(true),
       has_been_bound_(false),
       samples_(0),
       internal_format_(GL_RGBA4),
@@ -175,6 +177,19 @@ void RenderbufferManager::SetCleared(Renderbuffer* renderbuffer,
   }
 }
 
+void RenderbufferManager::SetCleared(Renderbuffer* renderbuffer,
+                                     GLenum attachment,
+                                     bool cleared) {
+  DCHECK(renderbuffer);
+  if (!renderbuffer->cleared()) {
+    --num_uncleared_renderbuffers_;
+  }
+  renderbuffer->set_cleared(attachment, cleared);
+  if (!renderbuffer->cleared()) {
+    ++num_uncleared_renderbuffers_;
+  }
+}
+
 void RenderbufferManager::CreateRenderbuffer(
     GLuint client_id, GLuint service_id) {
   scoped_refptr<Renderbuffer> renderbuffer(