Enable GPU blacklist in tests.

gpu/config/gpu_control_list.h

Index: gpu/config/gpu_control_list.h
diff --git a/gpu/config/gpu_control_list.h b/gpu/config/gpu_control_list.h
index 62b66ec27824472c5488e2b60e34b3c3cd0ccec7..40f5b5d6f9b16cb67dabe684330cbedf4b50c33e 100644
--- a/gpu/config/gpu_control_list.h
+++ b/gpu/config/gpu_control_list.h
@@ -96,6 +96,9 @@ class GPU_EXPORT GpuControlList {
   // Register whether "all" is recognized as all features.
   void set_supports_feature_type_all(bool supported);
 
+  // Enables logging of blacklist decisions.
+  void enable_blacklist_logging() { blacklist_logging_enabled_ = true; }
+
  private:
   friend class GpuControlListEntryTest;
   friend class MachineModelInfoTest;
@@ -292,6 +295,9 @@ class GPU_EXPORT GpuControlList {
         const FeatureMap& feature_map,
         bool supports_feature_type_all);
 
+    // Logs a blacklist match for this rule.
+    void LogBlacklistMatch() const;
+
     // Determines if a given os/gc/machine_model/driver is included in the
     // Entry set.
     bool Contains(OsType os_type, const std::string& os_version,
@@ -495,6 +501,8 @@ class GPU_EXPORT GpuControlList {
   // The features a GpuControlList recognizes and handles.
   FeatureMap feature_map_;
   bool supports_feature_type_all_;
+
+  bool blacklist_logging_enabled_;
 };
 
 }  // namespace gpu