clean-up and clarify CreatePlatformCanvas methods

ui/surface/transport_dib_posix.cc

Index: ui/surface/transport_dib_posix.cc
diff --git a/ui/surface/transport_dib_posix.cc b/ui/surface/transport_dib_posix.cc
index 8beba1f7e5cf62567502c7228622ba483fc44e3a..5f68581d7d0de37d40e1b7b106033674ba81270b 100644
--- a/ui/surface/transport_dib_posix.cc
+++ b/ui/surface/transport_dib_posix.cc
@@ -63,9 +63,9 @@ std::unique_ptr<SkCanvas> TransportDIB::GetPlatformCanvas(int w,
                                                           bool opaque) {
   if ((!memory() && !Map()) || !VerifyCanvasSize(w, h))
     return NULL;
-  return skia::CreatePlatformCanvas(w, h, opaque,
-                                    reinterpret_cast<uint8_t*>(memory()),
-                                    skia::RETURN_NULL_ON_FAILURE);
+  return skia::CreatePlatformCanvasWithPixels(
+      w, h, opaque, reinterpret_cast<uint8_t*>(memory()),
+      skia::RETURN_NULL_ON_FAILURE);
 }
 
 bool TransportDIB::Map() {