Don't enable occlusion query on Linux with Intel drivers.

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/string_number_conversions.h"
+#include "base/string_util.h"
 #include "gpu/command_buffer/service/gl_utils.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_implementation.h"
 #if defined(OS_MACOSX)
 #include "ui/surface/io_surface_support_mac.h"
 #endif
 
 namespace gpu {
 namespace gles2 {
 
@@ skipping 81 matching lines @@
 
 void FeatureInfo::AddFeatures(const char* desired_features) {
   // Figure out what extensions to turn on.
   ExtensionHelper ext(
       // Some unittests execute without a context made current
       // so fall back to glGetString
       gfx::GLContext::GetCurrent() ?
           gfx::GLContext::GetCurrent()->GetExtensions().c_str() :
           reinterpret_cast<const char*>(glGetString(GL_EXTENSIONS)),
       desired_features);
+  const char* vendor_str = reinterpret_cast<const char*>(
+      glGetString(GL_VENDOR));
+  if (vendor_str) {
+    std::string str(StringToLowerASCII(std::string(vendor_str)));
+    feature_flags_.is_intel = str.find("intel") != std::string::npos;
+    feature_flags_.is_nvidia = str.find("nvidia") != std::string::npos;
+    feature_flags_.is_amd =
+        str.find("amd") != std::string::npos ||
+        str.find("ati") != std::string::npos;
+  }
 
   bool npot_ok = false;
 
   AddExtensionString("GL_CHROMIUM_resource_safe");
   AddExtensionString("GL_CHROMIUM_resize");
   AddExtensionString("GL_CHROMIUM_strict_attribs");
   AddExtensionString("GL_CHROMIUM_rate_limit_offscreen_context");
   AddExtensionString("GL_CHROMIUM_set_visibility");
   AddExtensionString("GL_CHROMIUM_gpu_memory_manager");
   AddExtensionString("GL_CHROMIUM_discard_framebuffer");
@@ skipping 318 matching lines @@
             GL_LUMINANCE16F_EXT);
         validators_.texture_internal_format_storage.AddValue(
             GL_LUMINANCE_ALPHA16F_EXT);
     }
   }
 
   bool have_ext_occlusion_query_boolean =
       ext.Have("GL_EXT_occlusion_query_boolean");
   bool have_arb_occlusion_query2 = ext.Have("GL_ARB_occlusion_query2");
   bool have_arb_occlusion_query = ext.Have("GL_ARB_occlusion_query");
-  if (ext.Desire("GL_EXT_occlusion_query_boolean") &&
+  bool ext_occlusion_query_disallowed = false;
+
+#if defined(OS_LINUX)
+  // Intel drivers on Linux appear to be buggy.
+  ext_occlusion_query_disallowed = feature_flags_.is_intel;
+#endif
+
+  if (!ext_occlusion_query_disallowed &&
+      ext.Desire("GL_EXT_occlusion_query_boolean") &&
       (have_ext_occlusion_query_boolean ||
        have_arb_occlusion_query2 ||
        have_arb_occlusion_query)) {
     AddExtensionString("GL_EXT_occlusion_query_boolean");
     feature_flags_.occlusion_query_boolean = true;
     feature_flags_.use_arb_occlusion_query2_for_occlusion_query_boolean =
         !have_ext_occlusion_query_boolean && have_arb_occlusion_query2;
     feature_flags_.use_arb_occlusion_query_for_occlusion_query_boolean =
         !have_ext_occlusion_query_boolean && have_arb_occlusion_query &&
         !have_arb_occlusion_query2;
@@ skipping 13 matching lines @@
 }
 
 void FeatureInfo::AddExtensionString(const std::string& str) {
   if (extensions_.find(str) == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 }  // namespace gles2
 }  // namespace gpu