Refactor read and write buffers.

Eliminates SkFlattenable{Read,Write}Buffer, promoting SkOrdered{Read,Write}Buffer
a step each in the hierarchy.

What used to be this:

SkFlattenableWriteBuffer -> SkOrderedWriteBuffer
SkFlattenableReadBuffer  -> SkOrderedReadBuffer
SkFlattenableReadBuffer  -> SkValidatingReadBuffer

is now

SkWriteBuffer
SkReadBuffer -> SkValidatingReadBuffer

Benefits:
  - code is simpler, names are less wordy
  - the generic SkFlattenableFooBuffer code in SkPaint was incorrect; removed
  - write buffers are completely devirtualized, important for record speed

This refactoring was mostly mechanical.  You aren't going to find anything
interesting in files with less than 10 lines changed.

BUG=skia:
R=reed@google.com, scroggo@google.com, djsollen@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/134163010

git-svn-id: http://skia.googlecode.com/svn/trunk@13245 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/FlatDataTest.cpp b/tests/FlatDataTest.cpp
index 1f0e12a..36fecf9 100644
--- a/tests/FlatDataTest.cpp
+++ b/tests/FlatDataTest.cpp
@@ -17,12 +17,12 @@
 #include "Test.h"
 
 struct SkFlattenableTraits {
-    static void flatten(SkOrderedWriteBuffer& buffer, const SkFlattenable& flattenable) {
+    static void flatten(SkWriteBuffer& buffer, const SkFlattenable& flattenable) {
         buffer.writeFlattenable(&flattenable);
     }
 };
 struct SkBitmapTraits {
-    static void flatten(SkOrderedWriteBuffer& buffer, const SkBitmap& bitmap) {
+    static void flatten(SkWriteBuffer& buffer, const SkBitmap& bitmap) {
         bitmap.flatten(buffer);
     }
 };