Revert of Make SkPngCodec decode progressively. (patchset #26 id:520001 of https://codereview.chromium.org/1997703003/ )

Reason for revert:
Still causing problems in Google3, e.g.

https://test.corp.google.com/ui#cl=124138817&flags=CAMQBQ==&id=OCL:124138817:BASE:124139560:1465227435491:219ffbdb&t=//third_party/skia/HEAD:dm

Original issue's description:
> Make SkPngCodec decode progressively.
>
> This is a step towards using SkCodec in Chromium, where progressive
> decoding is necessary.
>
> Switch from using png_read_row (which expects all the data to be
> available) to png_process_data, which uses callbacks when rows are
> available.
>
> Create a new API for SkCodec, which supports progressive decoding and
> scanline decoding. Future changes will switch the other clients off of
> startScanlineDecode and get/skip-Scanlines to the new API.
>
> Remove SkCodec::kNone_ScanlineOrder, which was only used for interlaced
> PNG images. In the new API, interlaced PNG fits kTopDown. Also remove
> updateCurrScanline(), which was only used by the old implementation for
> interlaced PNG.
>
> DMSrcSink:
> - In CodecSrc::kScanline_Mode, use the new method for scanline decoding
> for the supported formats (just PNG and PNG-in-ICO for now).
>
> fuzz.cpp:
> - Remove reference to kNone_ScanlineOrder
>
> SkCodec:
> - Add new APIs:
>     - startIncrementalDecode
>     - incrementalDecode
> - Remove kNone_SkScanlineOrder and updateCurrScanline()
>
> SkPngCodec:
> - Implement new APIs
> - Switch from sk_read_fn/png_read_row etc to png_process_data
> - Expand AutoCleanPng's role to decode the header and create the
>   SkPngCodec
> - Make the interlaced PNG decoder report how many lines were
>   initialized during an incomplete decode
> - Make initializeSwizzler return a bool instead of an SkCodec::Result
>   (It only returned kSuccess or kInvalidInput anyway)
>
> SkIcoCodec:
> - Implement the new APIs; supported for PNG in ICO
>
> SkSampledCodec:
> - Call the new method for decoding scanlines, and fall back to the old
>   method if the new version is unimplemented
> - Remove references to kNone_SkScanlineOrder
>
> tests/CodecPartial:
> - Add a test which decodes part of an image, then finishes the decode,
>   and compares it to the straightforward method
>
> tests/CodecTest:
> - Add a test which decodes all scanlines using the new method
> - Repurpose the Codec_stripes test to decode using the new method in
>   sections rather than all at once
> - In the method check(), add a parameter for whether the image supports
>   the new method of scanline decoding, and be explicit about whether an
>   image supports incomplete
> - Test incomplete PNG decodes. We should have been doing it anyway for
>   non-interlaced (except for an image that is too small - one row), but
>   the new method supports interlaced incomplete as well
> - Make test_invalid_parameters test the new method
> - Add a test to ensure that it's safe to fall back to scanline decoding without
>   rewinding
>
> BUG=skia:4211
>
> The new version was generally faster than the old version (but not significantly so).
>
> Some raw performance differences can be found at https://docs.google.com/a/google.com/spreadsheets/d/1Gis3aRCEa72qBNDRMgGDg3jD-pMgO-FXldlNF9ejo4o/
>
> Design doc can be found at https://docs.google.com/a/google.com/document/d/11Mn8-ePDKwVEMCjs3nWwSjxcSpJ_Cu8DF57KNtUmgLM/
>
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1997703003
>
> Committed: https://skia.googlesource.com/skia/+/a4b09a117d4d1ba5dda372e6a2323e653766539e
>
> Committed: https://skia.googlesource.com/skia/+/30e78c9737ff4861dc4e3fa1e4cd010680ed6965
>
> Committed: https://skia.googlesource.com/skia/+/6fb2391b2cc83ee2160b4e994faa8128975acc1f

TBR=reed@google.com,msarett@google.com,scroggo@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=skia:4211
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2044573002

Review-Url: https://codereview.chromium.org/2044573002

1 files changed, 19 insertions, 76 deletions

diff --git a/include/codec/SkCodec.h b/include/codec/SkCodec.h
index d2e101dea4..293068c2de 100644
--- a/include/codec/SkCodec.h
+++ b/include/codec/SkCodec.h
@@ -24,11 +24,11 @@ class SkPngChunkReader;
 class SkSampler;
 
 namespace DM {
-class CodecSrc;
 class ColorCodecSrc;
 }
 class ColorCodecBench;
 
+
 /**
  *  Abstraction layer directly on top of an image codec.
  */
@@ -259,8 +259,8 @@ public:
          *  If the EncodedFormat is kWEBP_SkEncodedFormat (the only one which
          *  currently supports subsets), the top and left values must be even.
          *
-         *  In getPixels and incremental decode, we will attempt to decode the
-         *  exact rectangular subset specified by fSubset.
+         *  In getPixels, we will attempt to decode the exact rectangular
+         *  subset specified by fSubset.
          *
          *  In a scanline decode, it does not make sense to specify a subset
          *  top or subset height, since the client already controls which rows
@@ -355,67 +355,6 @@ public:
     }
 
     /**
-     *  Prepare for an incremental decode with the specified options.
-     *
-     *  This may require a rewind.
-     *
-     *  @param dstInfo Info of the destination. If the dimensions do not match
-     *      those of getInfo, this implies a scale.
-     *  @param dst Memory to write to. Needs to be large enough to hold the subset,
-     *      if present, or the full image as described in dstInfo.
-     *  @param options Contains decoding options, including if memory is zero
-     *      initialized and whether to decode a subset.
-     *  @param ctable A pointer to a color table.  When dstInfo.colorType() is
-     *      kIndex8, this should be non-NULL and have enough storage for 256
-     *      colors.  The color table will be populated after decoding the palette.
-     *  @param ctableCount A pointer to the size of the color table.  When
-     *      dstInfo.colorType() is kIndex8, this should be non-NULL.  It will
-     *      be modified to the true size of the color table (<= 256) after
-     *      decoding the palette.
-     *  @return Enum representing success or reason for failure.
-     */
-    Result startIncrementalDecode(const SkImageInfo& dstInfo, void* dst, size_t rowBytes,
-            const SkCodec::Options*, SkPMColor* ctable, int* ctableCount);
-
-    Result startIncrementalDecode(const SkImageInfo& dstInfo, void* dst, size_t rowBytes,
-            const SkCodec::Options* options) {
-        return this->startIncrementalDecode(dstInfo, dst, rowBytes, options, nullptr, nullptr);
-    }
-
-    Result startIncrementalDecode(const SkImageInfo& dstInfo, void* dst, size_t rowBytes) {
-        return this->startIncrementalDecode(dstInfo, dst, rowBytes, nullptr, nullptr, nullptr);
-    }
-
-    /**
-     *  Start/continue the incremental decode.
-     *
-     *  Not valid to call before calling startIncrementalDecode().
-     *
-     *  After the first call, should only be called again if more data has been
-     *  provided to the source SkStream.
-     *
-     *  Unlike getPixels and getScanlines, this does not do any filling. This is
-     *  left up to the caller, since they may be skipping lines or continuing the
-     *  decode later. In the latter case, they may choose to initialize all lines
-     *  first, or only initialize the remaining lines after the first call.
-     *
-     *  @param rowsDecoded Optional output variable returning the total number of
-     *      lines initialized. Only meaningful if this method returns kIncompleteInput.
-     *      Otherwise the implementation may not set it.
-     *      Note that some implementations may have initialized this many rows, but
-     *      not necessarily finished those rows (e.g. interlaced PNG). This may be
-     *      useful for determining what rows the client needs to initialize.
-     *  @return kSuccess if all lines requested in startIncrementalDecode have
-     *      been completely decoded. kIncompleteInput otherwise.
-     */
-    Result incrementalDecode(int* rowsDecoded = nullptr) {
-        if (!fStartedIncrementalDecode) {
-            return kInvalidParameters;
-        }
-        return this->onIncrementalDecode(rowsDecoded);
-    }
-
-    /**
      * The remaining functions revolve around decoding scanlines.
      */
 
@@ -535,6 +474,17 @@ public:
          * Interlaced gifs are an example.
          */
         kOutOfOrder_SkScanlineOrder,
+
+        /*
+         * Indicates that the entire image must be decoded in order to output
+         * any amount of scanlines.  In this case, it is a REALLY BAD IDEA to
+         * request scanlines 1-by-1 or in small chunks.  The client should
+         * determine which scanlines are needed and ask for all of them in
+         * a single call to getScanlines().
+         *
+         * Interlaced pngs are an example.
+         */
+        kNone_SkScanlineOrder,
     };
 
     /**
@@ -683,6 +633,11 @@ protected:
      */
     virtual SkScanlineOrder onGetScanlineOrder() const { return kTopDown_SkScanlineOrder; }
 
+    /**
+     *  Update the current scanline. Used by interlaced png.
+     */
+    void updateCurrScanline(int newY) { fCurrScanline = newY; }
+
     const SkImageInfo& dstInfo() const { return fDstInfo; }
 
     const SkCodec::Options& options() const { return fOptions; }
@@ -714,7 +669,6 @@ private:
     SkImageInfo                 fDstInfo;
     SkCodec::Options            fOptions;
     int                         fCurrScanline;
-    bool                        fStartedIncrementalDecode;
 
     /**
      *  Return whether these dimensions are supported as a scale.
@@ -735,16 +689,6 @@ private:
         return kUnimplemented;
     }
 
-    virtual Result onStartIncrementalDecode(const SkImageInfo& /*dstInfo*/, void*, size_t,
-            const SkCodec::Options&, SkPMColor*, int*) {
-        return kUnimplemented;
-    }
-
-    virtual Result onIncrementalDecode(int*) {
-        return kUnimplemented;
-    }
-
-
     virtual bool onSkipScanlines(int /*countLines*/) { return false; }
 
     virtual int onGetScanlines(void* /*dst*/, int /*countLines*/, size_t /*rowBytes*/) { return 0; }
@@ -781,7 +725,6 @@ private:
     friend class DM::ColorCodecSrc;
     friend class ColorCodecBench;
 
-    friend class DM::CodecSrc;  // for fillIncompleteImage
     friend class SkSampledCodec;
     friend class SkIcoCodec;
 };