gpu: support immutable texture on Linux Mesa driver and GLES3.

gpu/command_buffer/service/feature_info.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/feature_info.h"
 
 #include <set>
 
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 378 matching lines @@
 
   if (extensions.Contains("GL_OES_element_index_uint") ||
       gfx::HasDesktopGLFeatures()) {
     AddExtensionString("GL_OES_element_index_uint");
     validators_.index_type.AddValue(GL_UNSIGNED_INT);
   }
 
   bool enable_texture_format_bgra8888 = false;
   bool enable_read_format_bgra = false;
   bool enable_render_buffer_bgra = false;
+  bool enable_immutable_texture_format_bgra_on_es3 =
+      extensions.Contains("GL_APPLE_texture_format_BGRA8888");
 
   // Check if we should allow GL_EXT_texture_format_BGRA8888
   if (extensions.Contains("GL_EXT_texture_format_BGRA8888") ||
-      extensions.Contains("GL_APPLE_texture_format_BGRA8888") ||
+      enable_immutable_texture_format_bgra_on_es3 ||
       extensions.Contains("GL_EXT_bgra")) {
     enable_texture_format_bgra8888 = true;
   }
 
   if (extensions.Contains("GL_EXT_bgra")) {
     enable_render_buffer_bgra = true;
   }
 
   if (extensions.Contains("GL_EXT_read_format_bgra") ||
       extensions.Contains("GL_EXT_bgra")) {
@@ skipping 272 matching lines @@
     validators_.pixel_store.AddValue(GL_PACK_REVERSE_ROW_ORDER_ANGLE);
     validators_.g_l_state.AddValue(GL_PACK_REVERSE_ROW_ORDER_ANGLE);
   }
 
   if (extensions.Contains("GL_ANGLE_texture_usage")) {
     feature_flags_.angle_texture_usage = true;
     AddExtensionString("GL_ANGLE_texture_usage");
     validators_.texture_parameter.AddValue(GL_TEXTURE_USAGE_ANGLE);
   }
 
-  if (extensions.Contains("GL_EXT_texture_storage")) {
+  // Note: Only APPLE_texture_format_BGRA8888 extension allows BGRA8_EXT in
+  // ES3's glTexStorage2D. We prefer support BGRA to texture storage.
+  // So we don't expose GL_EXT_texture_storage when ES3 +
+  // GL_EXT_texture_format_BGRA8888 because we fail the GL_BGRA8 requirement.
+  // However we expose GL_EXT_texture_storage when just ES3 because we don't
+  // claim to handle GL_BGRA8.
+  bool support_texture_storage_on_es3 =
+      (is_es3 && enable_immutable_texture_format_bgra_on_es3) ||
+      (is_es3 && !enable_texture_format_bgra8888);
+  if (extensions.Contains("GL_EXT_texture_storage") ||
+      extensions.Contains("GL_ARB_texture_storage") ||
+      support_texture_storage_on_es3) {
     feature_flags_.ext_texture_storage = true;
     AddExtensionString("GL_EXT_texture_storage");
     validators_.texture_parameter.AddValue(GL_TEXTURE_IMMUTABLE_FORMAT_EXT);
     if (enable_texture_format_bgra8888)
         validators_.texture_internal_format_storage.AddValue(GL_BGRA8_EXT);
     if (enable_texture_float) {
         validators_.texture_internal_format_storage.AddValue(GL_RGBA32F_EXT);
         validators_.texture_internal_format_storage.AddValue(GL_RGB32F_EXT);
         validators_.texture_internal_format_storage.AddValue(GL_ALPHA32F_EXT);
         validators_.texture_internal_format_storage.AddValue(
@@ skipping 148 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu