use anon namespace to avoid (silent) collisions between local test classes

BUG=skia:
TBR=

Review URL: https://codereview.chromium.org/1079813002

1 files changed, 2 insertions, 0 deletions

diff --git a/gm/drawfilter.cpp b/gm/drawfilter.cpp
index 40323c9ac8..8c29f07b02 100644
--- a/gm/drawfilter.cpp
+++ b/gm/drawfilter.cpp
@@ -19,6 +19,7 @@
  * the second red and sharp.
  */
 
+namespace {
 class TestFilter : public SkDrawFilter {
 public:
     bool filter(SkPaint* p, Type) override {
@@ -27,6 +28,7 @@ public:
         return true;
     }
 };
+}
 
 class DrawFilterGM : public skiagm::GM {
     SkAutoTUnref<SkMaskFilter> fBlur;