Revert "Remove support for decoding to kIndex_8"

This reverts commit 742a3e298fda669006147e4a305bab8452369b1f.

Reason for revert: Breaking Android roll:
frameworks/base/core/jni/android/graphics/BitmapFactory.cpp:453:18: error: no member named 'fColorPtr' in 'SkAndroidCodec::AndroidOptions'
    codecOptions.fColorPtr = colorPtr;
    ~~~~~~~~~~~~ ^
frameworks/base/core/jni/android/graphics/BitmapFactory.cpp:454:18: error: no member named 'fColorCount' in 'SkAndroidCodec::AndroidOptions'
    codecOptions.fColorCount = colorCount;
    ~~~~~~~~~~~~ ^

Original change's description:
> Remove support for decoding to kIndex_8
> 
> Fix up callsites, and remove tests that no longer make sense.
> 
> Bug: skia:6828
> Change-Id: I2548c4b7528b7b1be7412563156f27b52c9d4295
> Reviewed-on: https://skia-review.googlesource.com/21664
> Reviewed-by: Derek Sollenberger <djsollen@google.com>
> Commit-Queue: Leon Scroggins <scroggo@google.com>

TBR=djsollen@google.com,scroggo@google.com

Change-Id: I1bc669441f250690884e75a9a61427fdf75c6907
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:6828
Reviewed-on: https://skia-review.googlesource.com/22120
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
diff --git a/src/codec/SkWbmpCodec.h b/src/codec/SkWbmpCodec.h
index e8a6e40..40f507e 100644
--- a/src/codec/SkWbmpCodec.h
+++ b/src/codec/SkWbmpCodec.h
@@ -26,13 +26,13 @@
 protected:
     SkEncodedImageFormat onGetEncodedFormat() const override;
     Result onGetPixels(const SkImageInfo&, void*, size_t,
-                       const Options&, int*) override;
+                       const Options&, SkPMColor[], int*, int*) override;
     bool onRewind() override;
 private:
     /*
      * Returns a swizzler on success, nullptr on failure
      */
-    SkSwizzler* initializeSwizzler(const SkImageInfo& info,
+    SkSwizzler* initializeSwizzler(const SkImageInfo& info, const SkPMColor* ctable,
                                    const Options& opts);
     SkSampler* getSampler(bool createIfNecessary) override {
         SkASSERT(fSwizzler || !createIfNecessary);
@@ -50,12 +50,13 @@
 
     // Used for scanline decodes:
     std::unique_ptr<SkSwizzler> fSwizzler;
+    sk_sp<SkColorTable>         fColorTable;
     SkAutoTMalloc<uint8_t>      fSrcBuffer;
 
     int onGetScanlines(void* dst, int count, size_t dstRowBytes) override;
     bool onSkipScanlines(int count) override;
-    Result onStartScanlineDecode(const SkImageInfo& dstInfo,
-            const Options& options) override;
+    Result onStartScanlineDecode(const SkImageInfo& dstInfo, const Options& options,
+            SkPMColor inputColorTable[], int* inputColorCount) override;
 
     typedef SkCodec INHERITED;
 };