Revert of Change call-sites now that SkCanvas is not ref-counted

content/browser/compositor/software_output_device_win.cc

Index: content/browser/compositor/software_output_device_win.cc
diff --git a/content/browser/compositor/software_output_device_win.cc b/content/browser/compositor/software_output_device_win.cc
index 2edf325b360a6681691ba6959ac103881b78519a..c48bed4fa0ebf03724dabf1197aee6e3aa61068d 100644
--- a/content/browser/compositor/software_output_device_win.cc
+++ b/content/browser/compositor/software_output_device_win.cc
@@ -139,9 +139,9 @@
       }
     }
     if (can_create_contents) {
-      contents_ = skia::CreatePlatformCanvas(
+      contents_ = sk_sp<SkCanvas>(skia::CreatePlatformCanvas(
           viewport_pixel_size_.width(), viewport_pixel_size_.height(), true,
-          shared_section, skia::CRASH_ON_FAILURE);
+          shared_section, skia::CRASH_ON_FAILURE));
     }
   }
 
@@ -192,6 +192,7 @@
 }
 
 void SoftwareOutputDeviceWin::ReleaseContents() {
+  DCHECK(!contents_ || contents_->unique());
   DCHECK(!in_paint_);
   contents_.reset();
 }