Revert of remove unused device::eraseColor

include/core/SkDevice.h

Index: include/core/SkDevice.h
diff --git a/include/core/SkDevice.h b/include/core/SkDevice.h
index 833e452fab93f6213b5bcfcd06cd41ffdbefcfcc..3c26baca5b012da04a84b38b470f926e6bb279dc 100644
--- a/include/core/SkDevice.h
+++ b/include/core/SkDevice.h
@@ -165,6 +165,9 @@
      *  Ignores the clip.
      */
     virtual void clear(SkColor color) = 0;
+
+    SK_ATTR_DEPRECATED("use clear() instead")
+    void eraseColor(SkColor eraseColor) { this->clear(eraseColor); }
 
     /** These are called inside the per-device-layer loop for each draw call.
      When these are called, we have already applied any saveLayer operations,