Revert of remove colorfilter native-565 support. complicating w/ no real value. (patchset #2 id:20001 of https://codereview.chromium.org/1015533011/)

Reason for revert:
skia/ext/benchmarking_canvas.cc references HasFilter16 :(

Original issue's description:
> remove colorfilter native-565 support. complicating w/ no real value.
>
> BUG=skia:
> TBR=
>
> Committed: https://skia.googlesource.com/skia/+/2151353d161fe389cdc0db62cfe1932c7680f710

TBR=reed@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1022673007

3 files changed, 23 insertions, 3 deletions

diff --git a/include/core/SkColorFilter.h b/include/core/SkColorFilter.h
index ea314811ba..fe151a2533 100644
--- a/include/core/SkColorFilter.h
+++ b/include/core/SkColorFilter.h
@@ -68,15 +68,31 @@ public:
         @param count    the number of entries in the src[] and result[] arrays
         @param result   written by the filter
     */
-    virtual void filterSpan(const SkPMColor src[], int count, SkPMColor result[]) const = 0;
+    virtual void filterSpan(const SkPMColor src[], int count,
+                            SkPMColor result[]) const = 0;
+    /** Called with a scanline of colors, as if there was a shader installed.
+        The implementation writes out its filtered version into result[].
+        Note: shader and result may be the same buffer.
+        @param src      array of colors, possibly generated by a shader
+        @param count    the number of entries in the src[] and result[] arrays
+        @param result   written by the filter
+    */
+    virtual void filterSpan16(const uint16_t shader[], int count,
+                              uint16_t result[]) const;
 
     enum Flags {
-        /** If set the filter methods will not change the alpha channel of the colors.
+        /** If set the filter methods will not change the alpha channel of the
+            colors.
         */
         kAlphaUnchanged_Flag = 0x01,
+        /** If set, this subclass implements filterSpan16(). If this flag is
+            set, then kAlphaUnchanged_Flag must also be set.
+        */
+        kHasFilter16_Flag    = 0x02
     };
 
-    /** Returns the flags for this filter. Override in subclasses to return custom flags.
+    /** Returns the flags for this filter. Override in subclasses to return
+        custom flags.
     */
     virtual uint32_t getFlags() const { return 0; }
 
diff --git a/include/effects/SkColorMatrixFilter.h b/include/effects/SkColorMatrixFilter.h
index 4cb24bad5d..7ec0a6f65c 100644
--- a/include/effects/SkColorMatrixFilter.h
+++ b/include/effects/SkColorMatrixFilter.h
@@ -20,7 +20,9 @@ public:
         return SkNEW_ARGS(SkColorMatrixFilter, (array));
     }
 
+    // overrides from SkColorFilter
     void filterSpan(const SkPMColor src[], int count, SkPMColor[]) const SK_OVERRIDE;
+    void filterSpan16(const uint16_t src[], int count, uint16_t[]) const SK_OVERRIDE;
     uint32_t getFlags() const SK_OVERRIDE;
     bool asColorMatrix(SkScalar matrix[20]) const SK_OVERRIDE;
     SkColorFilter* newComposed(const SkColorFilter*) const SK_OVERRIDE;
diff --git a/include/effects/SkModeColorFilter.h b/include/effects/SkModeColorFilter.h
index 6d0d3ccaa0..4bb7a43db4 100644
--- a/include/effects/SkModeColorFilter.h
+++ b/include/effects/SkModeColorFilter.h
@@ -28,6 +28,7 @@ public:
     bool asColorMode(SkColor*, SkXfermode::Mode*) const SK_OVERRIDE;
     uint32_t getFlags() const SK_OVERRIDE;
     void filterSpan(const SkPMColor shader[], int count, SkPMColor result[]) const SK_OVERRIDE;
+    void filterSpan16(const uint16_t shader[], int count, uint16_t result[]) const SK_OVERRIDE;
 
 #ifndef SK_IGNORE_TO_STRING
     void toString(SkString* str) const SK_OVERRIDE {
@@ -52,6 +53,7 @@ private:
     // cache
     SkPMColor           fPMColor;
     SkXfermodeProc      fProc;
+    SkXfermodeProc16    fProc16;
 
     void updateCache();