Initial error handling code

I made it as simple as possible. The impact seems minimal and it should do what's necessary to make this code secure.

BUG=

Committed: http://code.google.com/p/skia/source/detail?r=11247

R=reed@google.com, scroggo@google.com, djsollen@google.com, sugoi@google.com, bsalomon@google.com, mtklein@google.com, senorblanco@google.com, senorblanco@chromium.org

Author: sugoi@chromium.org

Review URL: https://codereview.chromium.org/23021015

git-svn-id: http://skia.googlecode.com/svn/trunk@11922 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkShader.h b/include/core/SkShader.h
index 74f611d..11956ce 100644
--- a/include/core/SkShader.h
+++ b/include/core/SkShader.h
@@ -344,6 +344,8 @@
 
     SkDEVCODE(virtual void toString(SkString* str) const;)
 
+    SK_DEFINE_FLATTENABLE_TYPE(SkShader)
+
 protected:
     enum MatrixClass {
         kLinear_MatrixClass,            // no perspective