Add SkDefaultXform as a catch-all to handle color conversions

src/core/SkColorSpace.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkColorSpace.h"
 #include "SkColorSpace_Base.h"
 #include "SkEndian.h"
@@ skipping 657 matching lines @@
 
     return true;
 }
 
 bool load_matrix(SkMatrix44* toXYZ, const uint8_t* src, size_t len) {
     if (len < 48) {
         SkColorSpacePrintf("Matrix tag is too small (%d bytes).", len);
         return false;
     }
 
+    // For this matrix to behave like our "to XYZ D50" matrices, it needs to be scaled.
+    constexpr float scale = 65535.0 / 32768.0;
     float array[16];
-    array[ 0] = SkFixedToFloat(read_big_endian_int(src));
-    array[ 1] = SkFixedToFloat(read_big_endian_int(src + 4));
-    array[ 2] = SkFixedToFloat(read_big_endian_int(src + 8));
-    array[ 3] = SkFixedToFloat(read_big_endian_int(src + 36)); // translate R
-    array[ 4] = SkFixedToFloat(read_big_endian_int(src + 12));
-    array[ 5] = SkFixedToFloat(read_big_endian_int(src + 16));
-    array[ 6] = SkFixedToFloat(read_big_endian_int(src + 20));
-    array[ 7] = SkFixedToFloat(read_big_endian_int(src + 40)); // translate G
-    array[ 8] = SkFixedToFloat(read_big_endian_int(src + 24));
-    array[ 9] = SkFixedToFloat(read_big_endian_int(src + 28));
-    array[10] = SkFixedToFloat(read_big_endian_int(src + 32));
-    array[11] = SkFixedToFloat(read_big_endian_int(src + 44)); // translate B
+    array[ 0] = scale * SkFixedToFloat(read_big_endian_int(src));
+    array[ 1] = scale * SkFixedToFloat(read_big_endian_int(src + 4));
+    array[ 2] = scale * SkFixedToFloat(read_big_endian_int(src + 8));
+    array[ 3] = scale * SkFixedToFloat(read_big_endian_int(src + 36)); // translate R
+    array[ 4] = scale * SkFixedToFloat(read_big_endian_int(src + 12));
+    array[ 5] = scale * SkFixedToFloat(read_big_endian_int(src + 16));
+    array[ 6] = scale * SkFixedToFloat(read_big_endian_int(src + 20));
+    array[ 7] = scale * SkFixedToFloat(read_big_endian_int(src + 40)); // translate G
+    array[ 8] = scale * SkFixedToFloat(read_big_endian_int(src + 24));
+    array[ 9] = scale * SkFixedToFloat(read_big_endian_int(src + 28));
+    array[10] = scale * SkFixedToFloat(read_big_endian_int(src + 32));
+    array[11] = scale * SkFixedToFloat(read_big_endian_int(src + 44)); // translate B
     array[12] = 0.0f;
     array[13] = 0.0f;
     array[14] = 0.0f;
     array[15] = 1.0f;
     toXYZ->setColMajorf(array);
     return true;
 }
 
 bool load_a2b0(SkColorLookUpTable* colorLUT, SkGammaCurve* gammas, SkMatrix44* toXYZ,
                const uint8_t* src, size_t len) {
@@ skipping 391 matching lines @@
     ptr32[4] = SkEndian_SwapBE32(0x000116cc);
     ptr += kTAG_XYZ_Bytes;
 
     // Write copyright tag
     memcpy(ptr, gEmptyTextTag, sizeof(gEmptyTextTag));
 
     // TODO (msarett): Should we try to hold onto the data so we can return immediately if
     //                 the client calls again?
     return SkData::MakeFromMalloc(profile.release(), kICCProfileSize);
 }