Fill incomplete images in SkCodec parent class

tests/CodexTest.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 "Resources.h"
 #include "SkBitmap.h"
 #include "SkCodec.h"
@@ skipping 141 matching lines @@
     REPORTER_ASSERT(r, codec->skipScanlines(1)
             == SkCodec::kScanlineDecodingNotStarted);
 
     const SkCodec::Result startResult = codec->startScanlineDecode(info);
     if (supportsScanlineDecoding) {
         bm.eraseColor(SK_ColorYELLOW);
 
         REPORTER_ASSERT(r, startResult == SkCodec::kSuccess);
 
         for (int y = 0; y < info.height(); y++) {
-            result = codec->getScanlines(bm.getAddr(0, y), 1, 0);
-            REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+            const uint32_t lines = codec->getScanlines(bm.getAddr(0, y), 1, 0);
+            REPORTER_ASSERT(r, 1 == lines);
         }
         // verify that scanline decoding gives the same result.
         if (SkCodec::kTopDown_SkScanlineOrder == codec->getScanlineOrder()) {
             compare_to_good_digest(r, digest, bm);
         }
 
         // Cannot continue to decode scanlines beyond the end
         REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
                 == SkCodec::kInvalidParameters);
 
@@ skipping 140 matching lines @@
     SkTDivMod(height, numStripes, &stripeHeight, &remainingLines);
 
     bm.eraseColor(SK_ColorYELLOW);
 
     result = codec->startScanlineDecode(info);
     REPORTER_ASSERT(r, result == SkCodec::kSuccess);
 
     // Odd stripes
     for (int i = 1; i < numStripes; i += 2) {
         // Skip the even stripes
-        result = codec->skipScanlines(stripeHeight);
-        REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+        bool skipResult = codec->skipScanlines(stripeHeight);
+        REPORTER_ASSERT(r, skipResult);
 
-        result = codec->getScanlines(bm.getAddr(0, i * stripeHeight), stripeHeight,
+        int linesDecoded = codec->getScanlines(bm.getAddr(0, i * stripeHeight), stripeHeight,
                                      bm.rowBytes());
-        REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+        REPORTER_ASSERT(r, linesDecoded == stripeHeight);
     }
 
     // Even stripes
     result = codec->startScanlineDecode(info);
     REPORTER_ASSERT(r, result == SkCodec::kSuccess);
 
     for (int i = 0; i < numStripes; i += 2) {
-        result = codec->getScanlines(bm.getAddr(0, i * stripeHeight), stripeHeight,
+        int linesDecoded = codec->getScanlines(bm.getAddr(0, i * stripeHeight), stripeHeight,
                                      bm.rowBytes());
-        REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+        REPORTER_ASSERT(r, linesDecoded == stripeHeight);
 
         // Skip the odd stripes
         if (i + 1 < numStripes) {
-            result = codec->skipScanlines(stripeHeight);
-            REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+            bool skipResult = codec->skipScanlines(stripeHeight);
+            REPORTER_ASSERT(r, skipResult);
         }
     }
 
     // Remainder at the end
     if (remainingLines > 0) {
         result = codec->startScanlineDecode(info);
         REPORTER_ASSERT(r, result == SkCodec::kSuccess);
 
-        result = codec->skipScanlines(height - remainingLines);
-        REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+        bool skipResult = codec->skipScanlines(height - remainingLines);
+        REPORTER_ASSERT(r, skipResult);
 
-        result = codec->getScanlines(bm.getAddr(0, height - remainingLines),
+        int linesDecoded = codec->getScanlines(bm.getAddr(0, height - remainingLines),
                                      remainingLines, bm.rowBytes());
-        REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+        REPORTER_ASSERT(r, linesDecoded == height - remainingLines);
     }
 
     compare_to_good_digest(r, digest, bm);
 }
 
 static void test_invalid_stream(skiatest::Reporter* r, const void* stream, size_t len) {
     SkCodec* codec = SkCodec::NewFromStream(new SkMemoryStream(stream, len, false));
     // We should not have gotten a codec. Bots should catch us if we leaked anything.
     REPORTER_ASSERT(r, !codec);
 }
@@ skipping 130 matching lines @@
     REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
     result = decoder->startScanlineDecode(
         decoder->getInfo().makeColorType(kIndex_8_SkColorType));
     REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
 }
 
 DEF_TEST(Codec_Params, r) {
     test_invalid_parameters(r, "index8.png");
     test_invalid_parameters(r, "mandrill.wbmp");
 }