Switch to a whitelist for manual mip-map generation

src/gpu/gl/GrGLUtil.cpp

Index: src/gpu/gl/GrGLUtil.cpp
diff --git a/src/gpu/gl/GrGLUtil.cpp b/src/gpu/gl/GrGLUtil.cpp
index ecc587b714ae33fe5b5e5eefa4fd9393b57bf28f..490e5010514896e0855f673465de98730ede1eab 100644
--- a/src/gpu/gl/GrGLUtil.cpp
+++ b/src/gpu/gl/GrGLUtil.cpp
@@ -252,6 +252,9 @@ GrGLVendor GrGLGetVendorFromString(const char* vendorString) {
         if (0 == strcmp(vendorString, "NVIDIA Corporation")) {
             return kNVIDIA_GrGLVendor;
         }
+        if (0 == strcmp(vendorString, "ATI Technologies Inc.")) {
+            return kATI_GrGLVendor;
+        }
     }
     return kOther_GrGLVendor;
 }