Scale the ALPHA_THRESHOLD filter's region based on the device scale factor.

cc/test/render_pass_test_common.cc

Index: cc/test/render_pass_test_common.cc
diff --git a/cc/test/render_pass_test_common.cc b/cc/test/render_pass_test_common.cc
index 9cbb98762fed11b80303c3e67b29d5f8f1e67990..8be896e5ac1a93147bed8541a0123a92780876a4 100644
--- a/cc/test/render_pass_test_common.cc
+++ b/cc/test/render_pass_test_common.cc
@@ -115,7 +115,8 @@ void TestRenderPass::AppendOneOfEveryQuadType(
                              rect,
                              gfx::RectF(),
                              FilterOperations(),
-                             FilterOperations());
+                             FilterOperations(),
+                             gfx::Vector2dF(1.f, 1.f));
     AppendQuad(render_pass_quad.PassAs<DrawQuad>());
 
     scoped_ptr<RenderPassDrawQuad> render_pass_replica_quad =
@@ -129,7 +130,8 @@ void TestRenderPass::AppendOneOfEveryQuadType(
                                      rect,
                                      gfx::RectF(),
                                      FilterOperations(),
-                                     FilterOperations());
+                                     FilterOperations(),
+                                     gfx::Vector2dF(1.f, 1.f));
     AppendQuad(render_pass_replica_quad.PassAs<DrawQuad>());
   }