Ignore gpu blacklists with kOverrideUseGLWithOSMesaForTests.

content/browser/gpu/gpu_data_manager_impl_private.cc

Index: content/browser/gpu/gpu_data_manager_impl_private.cc
diff --git a/content/browser/gpu/gpu_data_manager_impl_private.cc b/content/browser/gpu/gpu_data_manager_impl_private.cc
index 613294c67a90769955202205876c42e059a9b774..c7162a7d75048ae232acd7290a7cef47684e6b85 100644
--- a/content/browser/gpu/gpu_data_manager_impl_private.cc
+++ b/content/browser/gpu/gpu_data_manager_impl_private.cc
@@ -575,11 +575,13 @@ void GpuDataManagerImplPrivate::Initialize() {
 
   std::string gpu_blacklist_string;
   std::string gpu_driver_bug_list_string;
-  if (!command_line->HasSwitch(switches::kIgnoreGpuBlacklist) &&
+  if (!force_osmesa &&
+      !command_line->HasSwitch(switches::kIgnoreGpuBlacklist) &&
       !command_line->HasSwitch(switches::kUseGpuInTests)) {
     gpu_blacklist_string = gpu::kSoftwareRenderingListJson;
   }
-  if (!command_line->HasSwitch(switches::kDisableGpuDriverBugWorkarounds)) {
+  if (!force_osmesa &&
+      !command_line->HasSwitch(switches::kDisableGpuDriverBugWorkarounds)) {
     gpu_driver_bug_list_string = gpu::kGpuDriverBugListJson;
   }
   InitializeImpl(gpu_blacklist_string,