Revert "Revert "Redefine the meaning of sample counts in GPU backend.""

Fixes gpu config default samples to be 1 and updates config parsing test accordingly.

This reverts commit c1ce2f7966babaae0deb150f93f1227ee5af9285.

Bug: skia:
Change-Id: I456973b1f52ced85a2011ea10fc49449bfc5846f
Reviewed-on: https://skia-review.googlesource.com/102147
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/tests/DeviceTest.cpp b/tests/DeviceTest.cpp
index 64b83fc..58369cc 100644
--- a/tests/DeviceTest.cpp
+++ b/tests/DeviceTest.cpp
@@ -81,7 +81,7 @@
     SkImageInfo ii = SkImageInfo::MakeN32Premul(2*kWidth, 2*kHeight);
 
     sk_sp<SkBaseDevice> gpuDev(SkGpuDevice::Make(context, SkBudgeted::kNo, ii,
-                                                 0, kBottomLeft_GrSurfaceOrigin, nullptr,
+                                                 1, kBottomLeft_GrSurfaceOrigin, nullptr,
                                                  GrMipMapped::kNo,
                                                  SkGpuDevice::kClear_InitContents));