force readbuffer clients to use specialized readFoo for flattenables

BUG=
R=mtklein@google.com

Review URL: https://codereview.chromium.org/26702002

git-svn-id: http://skia.googlecode.com/svn/trunk@11803 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkFilterShader.cpp b/src/core/SkFilterShader.cpp
index 4fcb936..1e590cb 100644
--- a/src/core/SkFilterShader.cpp
+++ b/src/core/SkFilterShader.cpp
@@ -22,8 +22,8 @@
 
 SkFilterShader::SkFilterShader(SkFlattenableReadBuffer& buffer)
     : INHERITED(buffer) {
-    fShader = buffer.readFlattenableT<SkShader>();
-    fFilter = buffer.readFlattenableT<SkColorFilter>();
+    fShader = buffer.readShader();
+    fFilter = buffer.readColorFilter();
 }
 
 SkFilterShader::~SkFilterShader() {