Fix -Wunused-parameter errors in SkCodec.h in Android

include/codec/SkCodec.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCodec_DEFINED
 #define SkCodec_DEFINED
 
@@ skipping 465 matching lines @@
     /**
      * Some subclasses will override this function, but this is a useful default for the color
      * types that we support.  Note that for color types that do not use the full 32-bits,
      * we will simply take the low bits of the fill value.
      *
      * kN32_SkColorType: Transparent or Black
      * kRGB_565_SkColorType: Black
      * kGray_8_SkColorType: Black
      * kIndex_8_SkColorType: First color in color table
      */
-    virtual uint32_t onGetFillValue(SkColorType colorType, SkAlphaType alphaType) const {
+    virtual uint32_t onGetFillValue(SkColorType /*colorType*/, SkAlphaType alphaType) const {
         return kOpaque_SkAlphaType == alphaType ? SK_ColorBLACK : SK_ColorTRANSPARENT;
     }
 
     /**
      * Get method for the input stream
      */
     SkStream* stream() {
         return fStream.get();
     }
 
@@ skipping 33 matching lines @@
      *  Either way, the same information will be passed to onGetPixels/onStart
      *  on success.
      *
      *  This must return true for a size returned from getScaledDimensions.
      */
     bool dimensionsSupported(const SkISize& dim) {
         return dim == fSrcInfo.dimensions() || this->onDimensionsSupported(dim);
     }
 
     // Methods for scanline decoding.
-    virtual SkCodec::Result onStartScanlineDecode(const SkImageInfo& dstInfo,
-            const SkCodec::Options& options, SkPMColor ctable[], int* ctableCount) {
+    virtual SkCodec::Result onStartScanlineDecode(const SkImageInfo& /*dstInfo*/,
+            const SkCodec::Options& /*options*/, SkPMColor* /*ctable*/, int* /*ctableCount*/) {
         return kUnimplemented;
     }
 
     // Naive default version just calls onGetScanlines on temp memory.
     virtual bool onSkipScanlines(int countLines) {
         // FIXME (msarett): Make this a pure virtual and always override this.
         SkAutoMalloc storage(fDstInfo.minRowBytes());
 
         // Note that we pass 0 to rowBytes so we continue to use the same memory.
         // Also note that while getScanlines checks that rowBytes is big enough,
         // onGetScanlines bypasses that check.
         // Calling the virtual method also means we do not double count
         // countLines.
         return countLines == this->onGetScanlines(storage.get(), countLines, 0);
     }
 
-    virtual int onGetScanlines(void* dst, int countLines, size_t rowBytes) { return 0; }
+    virtual int onGetScanlines(void* /*dst*/, int /*countLines*/, size_t /*rowBytes*/) { return 0; }
 
     /**
      * On an incomplete decode, getPixels() and getScanlines() will call this function
      * to fill any uinitialized memory.
      *
      * @param dstInfo        Contains the destination color type
      *                       Contains the destination alpha type
      *                       Contains the destination width
      *                       The height stored in this info is unused
      * @param dst            Pointer to the start of destination pixel memory
      * @param rowBytes       Stride length in destination pixel memory
      * @param zeroInit       Indicates if memory is zero initialized
      * @param linesRequested Number of lines that the client requested
      * @param linesDecoded   Number of lines that were successfully decoded
      */
     void fillIncompleteImage(const SkImageInfo& dstInfo, void* dst, size_t rowBytes,
             ZeroInitialized zeroInit, int linesRequested, int linesDecoded);
 
     /**
      *  Return an object which will allow forcing scanline decodes to sample in X.
      *
      *  May create a sampler, if one is not currently being used. Otherwise, does
      *  not affect ownership.
      *
      *  Only valid during scanline decoding.
      */
-    virtual SkSampler* getSampler(bool createIfNecessary) { return nullptr; }
+    virtual SkSampler* getSampler(bool /*createIfNecessary*/) { return nullptr; }
 
     friend class SkSampledCodec;
 };
 #endif // SkCodec_DEFINED