Revert of Remove unused (by clients) SkUnitMapper (https://codereview.chromium.org/283273002/) (https://codereview.chromium.org/288343009/)

Reason for revert:
required blink change failed to land

Original issue's description:
> Remove unused (by clients) SkUnitMapper (https://codereview.chromium.org/283273002/)
>
> This reverts commit dd50c83b5b34dab3a077741861b50ed1f2bc6b8f.
>
> BUG=skia:
>
> Committed: http://code.google.com/p/skia/source/detail?r=14830

R=scroggo@google.com, reed@google.com
TBR=reed@google.com, scroggo@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Author: reed@chromium.org

Review URL: https://codereview.chromium.org/296823008

git-svn-id: http://skia.googlecode.com/svn/trunk@14838 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleSlides.cpp b/samplecode/SampleSlides.cpp
index 6bc9a28..d828ae6 100644
--- a/samplecode/SampleSlides.cpp
+++ b/samplecode/SampleSlides.cpp
@@ -178,26 +178,32 @@
 { 5, gColors, gPos2 }
 };
 
-static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
-    return SkGradientShader::CreateLinear(pts, data.fColors, data.fPos, data.fCount, tm);
+static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data,
+                            SkShader::TileMode tm, SkUnitMapper* mapper) {
+    return SkGradientShader::CreateLinear(pts, data.fColors, data.fPos,
+                                          data.fCount, tm, mapper);
 }
 
-static SkShader* MakeRadial(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
+static SkShader* MakeRadial(const SkPoint pts[2], const GradData& data,
+                            SkShader::TileMode tm, SkUnitMapper* mapper) {
     SkPoint center;
     center.set(SkScalarAve(pts[0].fX, pts[1].fX),
                SkScalarAve(pts[0].fY, pts[1].fY));
     return SkGradientShader::CreateRadial(center, center.fX, data.fColors,
-                                          data.fPos, data.fCount, tm);
+                                          data.fPos, data.fCount, tm, mapper);
 }
 
-static SkShader* MakeSweep(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
+static SkShader* MakeSweep(const SkPoint pts[2], const GradData& data,
+                           SkShader::TileMode tm, SkUnitMapper* mapper) {
     SkPoint center;
     center.set(SkScalarAve(pts[0].fX, pts[1].fX),
                SkScalarAve(pts[0].fY, pts[1].fY));
-    return SkGradientShader::CreateSweep(center.fX, center.fY, data.fColors, data.fPos, data.fCount);
+    return SkGradientShader::CreateSweep(center.fX, center.fY, data.fColors,
+                                         data.fPos, data.fCount, mapper);
 }
 
-static SkShader* Make2Radial(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
+static SkShader* Make2Radial(const SkPoint pts[2], const GradData& data,
+                             SkShader::TileMode tm, SkUnitMapper* mapper) {
     SkPoint center0, center1;
     center0.set(SkScalarAve(pts[0].fX, pts[1].fX),
                 SkScalarAve(pts[0].fY, pts[1].fY));
@@ -206,10 +212,11 @@
     return SkGradientShader::CreateTwoPointRadial(
                                                   center1, (pts[1].fX - pts[0].fX) / 7,
                                                   center0, (pts[1].fX - pts[0].fX) / 2,
-                                                  data.fColors, data.fPos, data.fCount, tm);
+                                                  data.fColors, data.fPos, data.fCount, tm, mapper);
 }
 
-typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm);
+typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data,
+                               SkShader::TileMode tm, SkUnitMapper* mapper);
 static const GradMaker gGradMakers[] = {
     MakeLinear, MakeRadial, MakeSweep, Make2Radial
 };
@@ -229,7 +236,7 @@
     for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) {
         canvas->save();
         for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers); j++) {
-            SkShader* shader = gGradMakers[j](pts, gGradData[i], tm);
+            SkShader* shader = gGradMakers[j](pts, gGradData[i], tm, NULL);
             paint.setShader(shader);
             canvas->drawRect(r, paint);
             shader->unref();
@@ -328,7 +335,7 @@
                       { SkIntToScalar(size.fX), SkIntToScalar(size.fY) } };
     SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorRED };
     return SkGradientShader::CreateLinear(pts, colors, NULL,
-                                          SK_ARRAY_COUNT(colors), SkShader::kMirror_TileMode);
+                                          SK_ARRAY_COUNT(colors), SkShader::kMirror_TileMode, NULL);
 }
 
 class Rec {