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

gpu/command_buffer/service/feature_info.cc

Index: gpu/command_buffer/service/feature_info.cc
diff --git a/gpu/command_buffer/service/feature_info.cc b/gpu/command_buffer/service/feature_info.cc
index de3eb5623ef77375cdcb2cb5091abb0413f575e4..004a75bbffe5b1c860b3602291ef8deb6caa02c2 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -236,11 +236,13 @@ void FeatureInfo::InitializeFeatures() {
     feature_flags_.is_angle = StartsWithASCII(renderer_str, "ANGLE", true);
   }
 
+  bool is_es = false;
   bool is_es3 = false;
   const char* version_str =
       reinterpret_cast<const char*>(glGetString(GL_VERSION));
   if (version_str) {
     std::string lstr(base::StringToLowerASCII(std::string(version_str)));
+    is_es = (lstr.substr(0, 9) == "opengl es");
     is_es3 = (lstr.substr(0, 12) == "opengl es 3.");
   }
 
@@ -396,10 +398,14 @@ void FeatureInfo::InitializeFeatures() {
   bool enable_texture_format_bgra8888 = false;
   bool enable_read_format_bgra = false;
   bool enable_render_buffer_bgra = false;
+  // Only APPLE_texture_format_BGRA8888 extension allows BGRA8_EXT in GLES's
+  // glTexStorage2D.
+  bool enable_immutable_texture_format_bgra_on_es =
+      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_es ||
       extensions.Contains("GL_EXT_bgra")) {
     enable_texture_format_bgra8888 = true;
   }
@@ -692,7 +698,12 @@ void FeatureInfo::InitializeFeatures() {
     validators_.texture_parameter.AddValue(GL_TEXTURE_USAGE_ANGLE);
   }
 
-  if (extensions.Contains("GL_EXT_texture_storage")) {
+  // Disable it if BGRA8_EXT isn't allowed.
+  bool support_bgra = (enable_texture_format_bgra8888 && !is_es) ||
+                      (enable_immutable_texture_format_bgra_on_es && is_es);
+  if (support_bgra &&
+      (extensions.Contains("GL_EXT_texture_storage") ||
+       extensions.Contains("GL_ARB_texture_storage") || is_es3)) {
     feature_flags_.ext_texture_storage = true;
     AddExtensionString("GL_EXT_texture_storage");
     validators_.texture_parameter.AddValue(GL_TEXTURE_IMMUTABLE_FORMAT_EXT);