Fix readback of 565 on Mac and enable tests

tests/ImageTest.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <functional>
 #include <initializer_list>
 #include "DMGpuSupport.h"
@@ skipping 47 matching lines @@
     SkPaint paint;
     paint.setColor(SK_ColorBLACK);
     canvas->drawRect(SkRect::MakeXYWH(5, 5, 10, 10), paint);
 }
 static SkImage* create_image() {
     const SkImageInfo info = SkImageInfo::MakeN32(20, 20, kOpaque_SkAlphaType);
     SkAutoTUnref<SkSurface> surface(SkSurface::NewRaster(info));
     draw_image_test_pattern(surface->getCanvas());
     return surface->newImageSnapshot();
 }
-#if 0
 static SkImage* create_image_565() {
     const SkImageInfo info = SkImageInfo::Make(20, 20, kRGB_565_SkColorType, kOpaque_SkAlphaType);
     SkAutoTUnref<SkSurface> surface(SkSurface::NewRaster(info));
     draw_image_test_pattern(surface->getCanvas());
     return surface->newImageSnapshot();
 }
-#endif
 static SkImage* create_image_ct() {
     SkPMColor colors[] = {
         SkPreMultiplyARGB(0xFF, 0xFF, 0xFF, 0x00),
         SkPreMultiplyARGB(0x80, 0x00, 0xA0, 0xFF),
         SkPreMultiplyARGB(0xFF, 0xBB, 0x00, 0xBB)
     };
     SkAutoTUnref<SkColorTable> colorTable(new SkColorTable(colors, SK_ARRAY_COUNT(colors)));
     uint8_t data[] = {
         0, 0, 0, 0, 0,
         0, 1, 1, 1, 0,
@@ skipping 707 matching lines @@
             if (pixelA != pixelB) {
                 ERRORF(reporter, "Expected image pixels to be the same. At %d,%d 0x%08x != 0x%08x",
                        x, y, pixelA, pixelB);
                 return;
             }
         }
     }
 }
 
 DEF_GPUTEST_FOR_RENDERING_CONTEXTS(NewTextureFromPixmap, reporter, context) {
-    for (auto create : {&create_image
-#if 0 // read pixels failing for non RT formats (565 not a RT on some desktop GLs).
-                        , &create_image_565
-#endif
-                        , &create_image_ct
-                        }) {
+    for (auto create : {&create_image,
+                        &create_image_565,
+                        &create_image_ct}) {
         SkAutoTUnref<SkImage> image((*create)());
         if (!image) {
             ERRORF(reporter, "Could not create image");
             return;
         }
 
         SkPixmap pixmap;
         if (!image->peekPixels(&pixmap)) {
             ERRORF(reporter, "peek failed");
         } else {
             SkAutoTUnref<SkImage> texImage(SkImage::NewTextureFromPixmap(context, pixmap,
                                                                          SkBudgeted::kNo));
             if (!texImage) {
                 ERRORF(reporter, "NewTextureFromPixmap failed.");
             } else {
                 check_images_same(reporter, image, texImage);
             }
         }
     }
 }
 
 #endif