Revert "remove legacy 255-biased colormatrix"

This reverts commit ec654f7397.

Reason for revert: Seems to be breaking the Google3 roll

Original change's description:
> remove legacy 255-biased colormatrix
> 
> Bug: skia:4872
> Bug: skia:9012
> 
> Change-Id: I7c1ac4e94405404fcb13079b5b578a5a26aad02e
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/210628
> Reviewed-by: Mike Reed <reed@google.com>
> Commit-Queue: Mike Reed <reed@google.com>
> Auto-Submit: Mike Reed <reed@google.com>

TBR=reed@google.com

Change-Id: Ib51de4f5a3f5d28b4870ca61fff43cce96e7426f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:4872, skia:9012
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/211587
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

include/core/SkColorFilter.h

@@ -37,6 +37,7 @@ public:
     bool asColorMode(SkColor* color, SkBlendMode* mode) const {
         return this->onAsAColorMode(color, mode);
     }
+    bool asColorMatrix(float rowMajor255[20]) const;
 
     /** If the filter can be represented by a source color plus Mode, this
      *  returns true, and sets (if not NULL) the color and mode appropriately.
@@ -139,6 +140,9 @@ private:
 
 class SK_API SkColorFilters {
 public:
+    // Deprecated: use Matrix(...) with 0...1 values for translate
+    static sk_sp<SkColorFilter> MatrixRowMajor255(const float array[20]);
+
     static sk_sp<SkColorFilter> Compose(sk_sp<SkColorFilter> outer, sk_sp<SkColorFilter> inner) {
         return outer ? outer->makeComposed(inner) : inner;
     }

src/core/SkColorFilter.cpp

@@ -32,6 +32,21 @@ bool SkColorFilter::onAsAColorMatrix(float matrix[20]) const {
     return false;
 }
 
+// DEPRECATED
+bool SkColorFilter::asColorMatrix(float rowMajor255[20]) const {
+    if (this->asAColorMatrix(rowMajor255)) {
+        if (rowMajor255) {
+            rowMajor255[ 4] *= 255;
+            rowMajor255[ 9] *= 255;
+            rowMajor255[14] *= 255;
+            rowMajor255[19] *= 255;
+        }
+        return true;
+    }
+    return false;
+}
+
+
 #if SK_SUPPORT_GPU
 std::unique_ptr<GrFragmentProcessor> SkColorFilter::asFragmentProcessor(
         GrRecordingContext*, const GrColorSpaceInfo&) const {

src/core/SkColorFilter_Matrix.cpp

@@ -16,6 +16,12 @@
 #include "src/core/SkReadBuffer.h"
 #include "src/core/SkWriteBuffer.h"
 
+static void scale_last_column(float rowMajor[20], float scale) {
+    for (int i = 0; i < 4; ++i) {
+        rowMajor[5*i + 4] *= scale;
+    }
+}
+
 void SkColorFilter_Matrix::initState() {
     const float* srcA = fMatrix + 15;
     fFlags = (srcA[0] == 0 && srcA[1] == 0 && srcA[2] == 0 && srcA[3] == 1 && srcA[4] == 0)
@@ -197,6 +203,14 @@ sk_sp<SkColorFilter> SkColorFilters::Matrix(const SkColorMatrix& cm) {
     return Matrix(cm.fMat);
 }
 
+// DEPRECATED
+sk_sp<SkColorFilter> SkColorFilters::MatrixRowMajor255(const float array[20]) {
+    float tmp[20];
+    memcpy(tmp, array, sizeof(tmp));
+    scale_last_column(tmp, 1.0f/255);
+    return Matrix(tmp);
+}
+
 void SkColorFilter_Matrix::RegisterFlattenables() {
     SK_REGISTER_FLATTENABLE(SkColorFilter_Matrix);
 
@@ -205,10 +219,7 @@ void SkColorFilter_Matrix::RegisterFlattenables() {
                             [](SkReadBuffer& buffer) -> sk_sp<SkFlattenable> {
         float matrix[20];
         if (buffer.readScalarArray(matrix, 20)) {
-            matrix[ 4] *= (1.0f/255);
-            matrix[ 9] *= (1.0f/255);
-            matrix[14] *= (1.0f/255);
-            matrix[19] *= (1.0f/255);
+            scale_last_column(matrix, 1.0f/255);
             return SkColorFilters::Matrix(matrix);
         }
         return nullptr;