Revert of It is dangerous to ignore SkRect::intersect's return value (patchset #6 id:100001 of https://codereview.chromium.org/833943002/)

Reason for revert:
Still more Chromium clean up to do

Original issue's description:
> It is dangerous to ignore SkRect::intersect's return value
>
> Committed: https://skia.googlesource.com/skia/+/152f524fd325b7776b01f84afbfe2fa071648a05

TBR=reed@google.com
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/825983005
diff --git a/gm/gmmain.cpp b/gm/gmmain.cpp
index 1652e61..ece8ff3 100644
--- a/gm/gmmain.cpp
+++ b/gm/gmmain.cpp
@@ -704,10 +704,8 @@
                 SkRect content = SkRect::MakeWH(SkIntToScalar(pageSize.width()),
                                                 SkIntToScalar(pageSize.height()));
                 initialTransform.mapRect(&content);
-                if (!content.intersect(0, 0, SkIntToScalar(pageSize.width()),
-                                       SkIntToScalar(pageSize.height()))) {
-                    content.setEmpty();
-                }
+                content.intersect(0, 0, SkIntToScalar(pageSize.width()),
+                                  SkIntToScalar(pageSize.height()));
                 SkISize contentSize =
                     SkISize::Make(SkScalarRoundToInt(content.width()),
                                   SkScalarRoundToInt(content.height()));