Add additional tests to ignored-tests

BUG=skia:

Review URL: https://codereview.chromium.org/463993003
diff --git a/expectations/gm/ignored-tests.txt b/expectations/gm/ignored-tests.txt
index b1dbec4..2e11566 100644
--- a/expectations/gm/ignored-tests.txt
+++ b/expectations/gm/ignored-tests.txt
@@ -50,4 +50,9 @@
 gradients_2pt_conical_edge
 gradients_2pt_conical_outside
 gradients_no_texture
+clamped_gradients
+srcmode
+complexclip2_rect_aa
+bigblurs
+simpleaaclip_rect