Reset TexImage2D base level to workaround Intel mac driver bug

gpu/command_buffer/service/texture_manager.cc

Index: gpu/command_buffer/service/texture_manager.cc
diff --git a/gpu/command_buffer/service/texture_manager.cc b/gpu/command_buffer/service/texture_manager.cc
index 3a655827f75efa7ac3312f866295dc400fda5642..31e4b8d9407e75acec20033600ac0e96de7d8c91 100644
--- a/gpu/command_buffer/service/texture_manager.cc
+++ b/gpu/command_buffer/service/texture_manager.cc
@@ -3261,12 +3261,22 @@ void TextureManager::DoTexImage(
           AdjustTexFormat(feature_info_.get(), args.format), args.type,
           args.pixels);
     } else {
+      if (texture_ref &&

[qiankun, 2017/04/26 04:16:20]

texture_ref should be always non-null here.

[yizhou.jiang, 2017/04/27 04:23:22]

Done.

+          feature_info_->workarounds().reset_teximage2d_base_level) {
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
+      }
       glTexImage2D(
           args.target, args.level,
           AdjustTexInternalFormat(feature_info_.get(), args.internal_format),
           args.width, args.height, args.border,
           AdjustTexFormat(feature_info_.get(), args.format), args.type,
           args.pixels);
+      if (texture_ref &&
+          feature_info_->workarounds().reset_teximage2d_base_level) {
+        Texture* texture = texture_ref->texture();
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL,
+                        texture->base_level());
+      }
     }
   }
   GLenum error = ERRORSTATE_PEEK_GL_ERROR(error_state, function_name);