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/GpuDrawPathTest.cpp b/tests/GpuDrawPathTest.cpp
index 012dc61..79afa63 100644
--- a/tests/GpuDrawPathTest.cpp
+++ b/tests/GpuDrawPathTest.cpp
@@ -78,7 +78,7 @@
 
 DEF_GPUTEST_FOR_ALL_GL_CONTEXTS(GpuDrawPath, reporter, ctxInfo) {
     for (auto& test_func : { &test_drawPathEmpty, &test_drawSameRectOvals }) {
-        for (auto& sampleCount : {0, 4, 16}) {
+        for (auto& sampleCount : {1, 4, 16}) {
             SkImageInfo info = SkImageInfo::MakeN32Premul(255, 255);
             auto surface(
                 SkSurface::MakeRenderTarget(ctxInfo.grContext(), SkBudgeted::kNo, info,