Create an SkAndroidCodec API separate from SkCodec

src/codec/SkWebpAdapterCodec.cpp

Index: src/codec/SkWebpAdapterCodec.cpp
diff --git a/src/codec/SkWebpAdapterCodec.cpp b/src/codec/SkWebpAdapterCodec.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..1a045cd3095adaf1e7fab49ad36b92785489e425
--- /dev/null
+++ b/src/codec/SkWebpAdapterCodec.cpp
@@ -0,0 +1,41 @@
+/*
+ * 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 "SkCodec.h"
+#include "SkCodecPriv.h"
+#include "SkWebpAdapterCodec.h"
+
+SkWebpAdapterCodec::SkWebpAdapterCodec(SkWebpCodec* codec)
+    : INHERITED(codec->getInfo())
+    , fCodec(codec)
+{}
+
+SkISize SkWebpAdapterCodec::onGetSampledDimensions(int sampleSize) const {
+    float scale = get_scale_from_sample_size(sampleSize);
+    return fCodec->getScaledDimensions(scale);
+}
+
+bool SkWebpAdapterCodec::onGetSubset(SkIRect* desiredSubset) const {
+    return fCodec->getValidSubset(desiredSubset);
+}
+
+SkISize SkWebpAdapterCodec::onGetSampledSubsetDimensions(int sampleSize, const SkIRect& subset)
+        const {
+    float scale = get_scale_from_sample_size(sampleSize);
+    int width = SkTMax(1, SkScalarRoundToInt(scale * (float) subset.width()));

[msarett, 2015/10/16 18:42:16]

Alternatively, we could use get_scaled_dimension() and be more uniform with
SkSampledCodec.

[scroggo, 2015/10/16 21:13:55]

I suppose this mimics the old behavior? I don't have a strong preference.

[msarett, 2015/10/19 16:06:10]

Using get_scaled_dimension() would actually be consistent with the old behavior.
 I think that's a good reason to use that.

+    int height = SkTMax(1, SkScalarRoundToInt(scale * (float) subset.height()));
+    return SkISize::Make(width, height);
+}
+
+SkCodec::Result SkWebpAdapterCodec::onGetAndroidPixels(const SkImageInfo& info, void* pixels,
+        size_t rowBytes, AndroidOptions& options) {
+    SkCodec::Options codecOptions;
+    codecOptions.fZeroInitialized = options.fZeroInitialized;
+    codecOptions.fSubset = options.fSubset;
+    return fCodec->getPixels(info, pixels, rowBytes, &codecOptions, options.fColorPtr,
+            options.fColorCount);
+}