Disabling mipmap generation until anisotropic mipmap levels are generated.

BUG=590804
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1744413002

Review URL: https://codereview.chromium.org/1744413002
diff --git a/src/gpu/GrImageIDTextureAdjuster.cpp b/src/gpu/GrImageIDTextureAdjuster.cpp
index 58dc5b9..5ba99d2 100644
--- a/src/gpu/GrImageIDTextureAdjuster.cpp
+++ b/src/gpu/GrImageIDTextureAdjuster.cpp
@@ -90,7 +90,8 @@
             return tex;
         }
     }
-
+    // disable mipmapping until we generate anisotropic mipmap levels
+    willBeMipped = false;
     if (willBeMipped) {
         tex = GrGenerateMipMapsAndUploadToTexture(this->context(), fBitmap);
     } else {