Revert 248ff023 & 2cb6cb72

Revert "SkImageEncoder: simplify API"
This reverts commit 248ff02331d7f73ee4b6c5a7eabeae1080c16cd4.
Revert "Fix bug: can't convert nullptr -> bool"
This reverts commit 2cb6cb7218171b357bb5c934f032ba69c7b78401.
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=5151
NOTRY=true

Change-Id: I5f6414392d6545f74db0b5bb50608d04f053a8ec
Reviewed-on: https://skia-review.googlesource.com/5151
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Hal Canary <halcanary@google.com>
diff --git a/tools/skdiff/skdiff_utils.cpp b/tools/skdiff/skdiff_utils.cpp
index f8eed90..f788ec8 100644
--- a/tools/skdiff/skdiff_utils.cpp
+++ b/tools/skdiff/skdiff_utils.cpp
@@ -6,7 +6,6 @@
  */
 #include "skdiff.h"
 #include "skdiff_utils.h"
-#include "sk_tool_utils.h"
 #include "SkBitmap.h"
 #include "SkCodec.h"
 #include "SkData.h"
@@ -83,8 +82,8 @@
     SkBitmap copy;
     bitmap.copyTo(&copy, kN32_SkColorType);
     force_all_opaque(copy);
-    return sk_tool_utils::EncodeImageToFile(path.c_str(), copy,
-                                      SkEncodedImageFormat::kPNG, 100);
+    return SkImageEncoder::EncodeFile(path.c_str(), copy,
+                                      SkImageEncoder::kPNG_Type, 100);
 }
 
 /// Return a copy of the "input" string, within which we have replaced all instances