SkImageEncoder: simplify API

(re-land 248ff02 & 2cb6cb7, with changes)

  - Hide SkImageEncoder class in private header.
  - SkImageEncoder::Type becomes SkEncodedImageFormat
  - SkEncodedFormat becomes SkEncodedImageFormat
  - SkImageEncoder static functions replaced with
    single function EncodeImage()
  - utility wrappers for EncodeImage() are in
    sk_tool_utils.h

TODO: remove link-time registration mechanism.
TODO: clean up clients use of API and flip the flag.
TODO: implement EncodeImage() in chromeium/skia/ext

Change-Id: I47d451e50be4d5c6c130869c7fa7c2857243d9f0
Reviewed-on: https://skia-review.googlesource.com/4909
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Reviewed-on: https://skia-review.googlesource.com/5186
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Hal Canary <halcanary@google.com>
diff --git a/dm/DM.cpp b/dm/DM.cpp
index d42a5f0..c3e3af4 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -524,17 +524,17 @@
     nativeModes.push_back(CodecSrc::kCodec_Mode);
     nativeModes.push_back(CodecSrc::kCodecZeroInit_Mode);
     switch (codec->getEncodedFormat()) {
-        case SkEncodedFormat::kJPEG_SkEncodedFormat:
+        case SkEncodedImageFormat::kJPEG:
             nativeModes.push_back(CodecSrc::kScanline_Mode);
             nativeModes.push_back(CodecSrc::kStripe_Mode);
             nativeModes.push_back(CodecSrc::kCroppedScanline_Mode);
             supportsNativeScaling = true;
             break;
-        case SkEncodedFormat::kWEBP_SkEncodedFormat:
+        case SkEncodedImageFormat::kWEBP:
             nativeModes.push_back(CodecSrc::kSubset_Mode);
             supportsNativeScaling = true;
             break;
-        case SkEncodedFormat::kDNG_SkEncodedFormat:
+        case SkEncodedImageFormat::kDNG:
             break;
         default:
             nativeModes.push_back(CodecSrc::kScanline_Mode);
@@ -547,7 +547,7 @@
     switch (codec->getInfo().colorType()) {
         case kGray_8_SkColorType:
             colorTypes.push_back(CodecSrc::kGrayscale_Always_DstColorType);
-            if (kWBMP_SkEncodedFormat == codec->getEncodedFormat()) {
+            if (SkEncodedImageFormat::kWBMP == codec->getEncodedFormat()) {
                 colorTypes.push_back(CodecSrc::kIndex8_Always_DstColorType);
             }
             break;
@@ -640,15 +640,15 @@
         push_image_gen_src(path, ImageGenSrc::kCodec_Mode, alphaType, false);
 
 #if defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
-        if (kWEBP_SkEncodedFormat != codec->getEncodedFormat() &&
-            kWBMP_SkEncodedFormat != codec->getEncodedFormat() &&
+        if (SkEncodedImageFormat::kWEBP != codec->getEncodedFormat() &&
+            SkEncodedImageFormat::kWBMP != codec->getEncodedFormat() &&
             kUnpremul_SkAlphaType != alphaType)
         {
             push_image_gen_src(path, ImageGenSrc::kPlatform_Mode, alphaType, false);
         }
 #elif defined(SK_BUILD_FOR_WIN)
-        if (kWEBP_SkEncodedFormat != codec->getEncodedFormat() &&
-            kWBMP_SkEncodedFormat != codec->getEncodedFormat())
+        if (SkEncodedImageFormat::kWEBP != codec->getEncodedFormat() &&
+            SkEncodedImageFormat::kWBMP != codec->getEncodedFormat())
         {
             push_image_gen_src(path, ImageGenSrc::kPlatform_Mode, alphaType, false);
         }