remove redundant/deprecated TwoPointRadial gradiet -- use TwoPointConical

This CL derived from https://codereview.chromium.org/1114243005/

BUG=skia:

Review URL: https://codereview.chromium.org/1117423003
diff --git a/src/gpu/GrProcessor.cpp b/src/gpu/GrProcessor.cpp
index 9be9e40..23f0ed1 100644
--- a/src/gpu/GrProcessor.cpp
+++ b/src/gpu/GrProcessor.cpp
@@ -49,7 +49,7 @@
  * we verify the count is as expected.  If a new factory is added, then these numbers must be
  * manually adjusted.
  */
-static const int kFPFactoryCount = 38;
+static const int kFPFactoryCount = 37;
 static const int kGPFactoryCount = 14;
 static const int kXPFactoryCount = 5;