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

src/core/SkReadBuffer.cpp

Index: src/core/SkReadBuffer.cpp
diff --git a/src/core/SkReadBuffer.cpp b/src/core/SkReadBuffer.cpp
index c32c7bd658672b3531900f3484363251223f91e1..d016d9c980b5ecbc77fc938a059c0cea11add3dc 100644
--- a/src/core/SkReadBuffer.cpp
+++ b/src/core/SkReadBuffer.cpp
@@ -335,25 +335,3 @@
     }
     return obj;
 }
-
-/**
- *  Needs to follow the same pattern as readFlattenable(), but explicitly skip whatever data
- *  has been written.
- */
-void SkReadBuffer::skipFlattenable() {
-    if (fFactoryCount > 0) {
-        if (0 == fReader.readU32()) {
-            return;
-        }
-    } else if (fFactoryTDArray) {
-        if (0 == fReader.readU32()) {
-            return;
-        }
-    } else {
-        if (NULL == this->readFunctionPtr()) {
-            return;
-        }
-    }
-    uint32_t sizeRecorded = fReader.readU32();
-    fReader.skip(sizeRecorded);
-}