Add GL State Restoring Functions

gpu/command_buffer/service/context_state.cc

Index: gpu/command_buffer/service/context_state.cc
diff --git a/gpu/command_buffer/service/context_state.cc b/gpu/command_buffer/service/context_state.cc
index 9942e9d249e3f071c353a68bf00dec794c17e581..7eaaa17805ab225a0aeba3d7ec5ef39a0422a777 100644
--- a/gpu/command_buffer/service/context_state.cc
+++ b/gpu/command_buffer/service/context_state.cc
@@ -44,7 +44,84 @@ ContextState::ContextState(FeatureInfo* feature_info)
 ContextState::~ContextState() {
 }
 
-void ContextState::RestoreState() const {
+void ContextState::RestoreTextureUnitBindings(GLuint unit) const {
+  DCHECK_LT(unit, texture_units.size());
+  const TextureUnit& texture_unit = texture_units[unit];
+  glActiveTexture(GL_TEXTURE0 + unit);
+  GLuint service_id = texture_unit.bound_texture_2d ?
+      texture_unit.bound_texture_2d->service_id() : 0;
+  glBindTexture(GL_TEXTURE_2D, service_id);
+  service_id = texture_unit.bound_texture_cube_map ?
+      texture_unit.bound_texture_cube_map->service_id() : 0;
+  glBindTexture(GL_TEXTURE_CUBE_MAP, service_id);
+
+  if (feature_info_->feature_flags().oes_egl_image_external) {
+    service_id = texture_unit.bound_texture_external_oes ?
+        texture_unit.bound_texture_external_oes->service_id() : 0;
+    glBindTexture(GL_TEXTURE_EXTERNAL_OES, service_id);
+  }
+
+  if (feature_info_->feature_flags().arb_texture_rectangle) {
+    service_id = texture_unit.bound_texture_rectangle_arb ?
+        texture_unit.bound_texture_rectangle_arb->service_id() : 0;
+    glBindTexture(GL_TEXTURE_RECTANGLE_ARB, service_id);
+  }
+}
+
+void ContextState::RestoreBufferBindings() const {
+  if (vertex_attrib_manager) {
+    BufferManager::BufferInfo* element_array_buffer =
+        vertex_attrib_manager->element_array_buffer();
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,
+        element_array_buffer ? element_array_buffer->service_id() : 0);
+  }
+  glBindBuffer(
+      GL_ARRAY_BUFFER,
+      bound_array_buffer ? bound_array_buffer->service_id() : 0);
+}
+
+void ContextState::RestoreRenderbufferBindings() const {
+  // Restore Bindings
+  glBindRenderbufferEXT(
+      GL_RENDERBUFFER,
+      bound_renderbuffer ? bound_renderbuffer->service_id() : 0);
+}
+
+void ContextState::RestoreProgramBindings() const {
+  glUseProgram(current_program ? current_program->service_id() : 0);
+}
+
+void ContextState::RestoreActiveTexture() const {
+  glActiveTexture(GL_TEXTURE0 + active_texture_unit);
+}
+
+void ContextState::RestoreAttribute(GLuint attrib) const {
+  const VertexAttribManager::VertexAttribInfo* info =
+      vertex_attrib_manager->GetVertexAttribInfo(attrib);
+  const void* ptr = reinterpret_cast<const void*>(info->offset());
+  BufferManager::BufferInfo* buffer_info = info->buffer();
+  glBindBuffer(
+      GL_ARRAY_BUFFER, buffer_info ? buffer_info->service_id() : 0);
+  glVertexAttribPointer(
+      attrib, info->size(), info->type(), info->normalized(),
+      info->gl_stride(), ptr);
+  if (info->divisor())
+    glVertexAttribDivisorANGLE(attrib, info->divisor());
+  // Never touch vertex attribute 0's state (in particular, never
+  // disable it) when running on desktop GL because it will never be
+  // re-enabled.
+  if (attrib != 0 ||
+      gfx::GetGLImplementation() == gfx::kGLImplementationEGLGLES2) {
+    if (info->enabled()) {
+      glEnableVertexAttribArray(attrib);
+    } else {
+      glDisableVertexAttribArray(attrib);
+    }
+  }
+  glVertexAttrib4fv(attrib, attrib_values[attrib].v);
+}
+
+void ContextState::RestoreGlobalState() const {
   InitCapabilities();
   InitState();
 
@@ -54,31 +131,14 @@ void ContextState::RestoreState() const {
   glHint(GL_GENERATE_MIPMAP_HINT, hint_generate_mipmap);
   // TODO: If OES_standard_derivatives is available
   // restore GL_FRAGMENT_SHADER_DERIVATIVE_HINT_OES
+}
 
+void ContextState::RestoreState() const {
   // Restore Texture state.
   for (size_t ii = 0; ii < texture_units.size(); ++ii) {
-    const TextureUnit& texture_unit = texture_units[ii];
-    glActiveTexture(GL_TEXTURE0 + ii);
-    GLuint service_id = texture_unit.bound_texture_2d ?
-        texture_unit.bound_texture_2d->service_id() : 0;
-    glBindTexture(GL_TEXTURE_2D, service_id);
-    service_id = texture_unit.bound_texture_cube_map ?
-        texture_unit.bound_texture_cube_map->service_id() : 0;
-    glBindTexture(GL_TEXTURE_CUBE_MAP, service_id);
-
-    if (feature_info_->feature_flags().oes_egl_image_external) {
-      service_id = texture_unit.bound_texture_external_oes ?
-          texture_unit.bound_texture_external_oes->service_id() : 0;
-      glBindTexture(GL_TEXTURE_EXTERNAL_OES, service_id);
-    }
-
-    if (feature_info_->feature_flags().arb_texture_rectangle) {
-      service_id = texture_unit.bound_texture_rectangle_arb ?
-          texture_unit.bound_texture_rectangle_arb->service_id() : 0;
-      glBindTexture(GL_TEXTURE_RECTANGLE_ARB, service_id);
-    }
+    RestoreTextureUnitBindings(ii);
   }
-  glActiveTexture(GL_TEXTURE0 + active_texture_unit);
+  RestoreActiveTexture();
 
   // Restore Attrib State
   // TODO: This if should not be needed. RestoreState is getting called
@@ -87,45 +147,12 @@ void ContextState::RestoreState() const {
     // TODO(gman): Move this restoration to VertexAttribManager.
     for (size_t attrib = 0; attrib < vertex_attrib_manager->num_attribs();
          ++attrib) {
-      const VertexAttribManager::VertexAttribInfo* info =
-          vertex_attrib_manager->GetVertexAttribInfo(attrib);
-      const void* ptr = reinterpret_cast<const void*>(info->offset());
-      BufferManager::BufferInfo* buffer_info = info->buffer();
-      glBindBuffer(
-          GL_ARRAY_BUFFER, buffer_info ? buffer_info->service_id() : 0);
-      glVertexAttribPointer(
-          attrib, info->size(), info->type(), info->normalized(),
-          info->gl_stride(), ptr);
-      if (info->divisor())
-        glVertexAttribDivisorANGLE(attrib, info->divisor());
-      // Never touch vertex attribute 0's state (in particular, never
-      // disable it) when running on desktop GL because it will never be
-      // re-enabled.
-      if (attrib != 0 ||
-          gfx::GetGLImplementation() == gfx::kGLImplementationEGLGLES2) {
-        if (info->enabled()) {
-          glEnableVertexAttribArray(attrib);
-        } else {
-          glDisableVertexAttribArray(attrib);
-        }
-      }
-      glVertexAttrib4fv(attrib, attrib_values[attrib].v);
+      RestoreAttribute(attrib);
     }
-    BufferManager::BufferInfo* element_array_buffer =
-        vertex_attrib_manager->element_array_buffer();
-    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,
-        element_array_buffer ? element_array_buffer->service_id() : 0);
   }
 
-  // Restore Bindings
-  glBindBuffer(
-      GL_ARRAY_BUFFER,
-      bound_array_buffer ? bound_array_buffer->service_id() : 0);
-  glBindRenderbufferEXT(
-      GL_RENDERBUFFER,
-      bound_renderbuffer ? bound_renderbuffer->service_id() : 0);
-
-  glUseProgram(current_program ? current_program->service_id() : 0);
+  RestoreRenderbufferBindings();
+  RestoreProgramBindings();
 }
 
 // Include the auto-generated part of this file. We split this because it means