Revert of remove colorfilter native-565 support. complicating w/ no real value.

include/core/SkColorFilter.h

Index: include/core/SkColorFilter.h
diff --git a/include/core/SkColorFilter.h b/include/core/SkColorFilter.h
index ea314811bae85fcaf09b9a28c801668fadfc6b29..fe151a2533fe71b07f110e6def629fc340b1105a 100644
--- a/include/core/SkColorFilter.h
+++ b/include/core/SkColorFilter.h
@@ -68,15 +68,31 @@
         @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; }