gpu: Use decoder state restoration for scoped_binders

gpu/command_buffer/service/context_state.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/context_state.h"
 
 #include <stddef.h>
 
 #include <cmath>
 
@@ skipping 59 matching lines @@
       return feature_info->feature_flags().arb_texture_rectangle;
     case GL_TEXTURE_EXTERNAL_OES:
       return feature_info->feature_flags().oes_egl_image_external ||
              feature_info->feature_flags().nv_egl_stream_consumer_external;
     default:
       NOTREACHED();
       return false;
   }
 }
 
+bool BufferTargetIsSupported(GLuint target) {
+  switch (target) {
+    case GL_ARRAY_BUFFER:
+      return true;
+    default:
+      NOTREACHED();
+      return false;
+  }
+}
+
 GLuint GetBufferId(const Buffer* buffer) {
   if (buffer)
     return buffer->service_id();
   return 0;
 }
 
 }  // anonymous namespace.
 
 TextureUnit::TextureUnit()
     : bind_target(GL_TEXTURE_2D) {
@@ skipping 209 matching lines @@
     glPixelStorei(GL_UNPACK_ROW_LENGTH, unpack_row_length);
     glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, unpack_image_height);
   }
 }
 
 void ContextState::DoLineWidth(GLfloat width) const {
   glLineWidth(
       std::min(std::max(width, line_width_min_), line_width_max_));
 }
 
+void ContextState::RestoreBufferBinding(unsigned int target) const {
+  if (BufferTargetIsSupported(target))

[piman, 2017/03/30 18:31:43]

Why this logic? Other targets *are* supported at the context level. It would be
extremely surprising for users to use a ScopedBufferBinder to not work based on
the target

[Chandan, 2017/03/30 19:22:39]

I added this logic to keep it consistent with !state_restorer_ case in
ScopedBufferBinder ctor.
So, target will be passed on to glBindBuffer without any check?

+    glBindBuffer(target, GetBufferId(bound_array_buffer.get()));
+}
+
 void ContextState::RestoreBufferBindings() const {
   if (vertex_attrib_manager.get()) {
     Buffer* element_array_buffer =
         vertex_attrib_manager->element_array_buffer();
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, GetBufferId(element_array_buffer));
   }
   glBindBuffer(GL_ARRAY_BUFFER, GetBufferId(bound_array_buffer.get()));
   if (feature_info_->IsES3Capable()) {
     glBindBuffer(GL_COPY_READ_BUFFER,
                  GetBufferId(bound_copy_read_buffer.get()));
@@ skipping 394 matching lines @@
   UpdateUnpackParameters();
 }
 
 // Include the auto-generated part of this file. 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 "gpu/command_buffer/service/context_state_impl_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu