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/src/core/SkImageInfo.cpp b/src/core/SkImageInfo.cpp
index 967b4f6..27c4573 100644
--- a/src/core/SkImageInfo.cpp
+++ b/src/core/SkImageInfo.cpp
@@ -6,7 +6,8 @@
  */
 
 #include "SkImageInfo.h"
-#include "SkFlattenableBuffers.h"
+#include "SkReadBuffer.h"
+#include "SkWriteBuffer.h"
 
 static bool alpha_type_is_valid(SkAlphaType alphaType) {
     return (alphaType >= 0) && (alphaType <= kLastEnum_SkAlphaType);
@@ -16,7 +17,7 @@
     return (colorType >= 0) && (colorType <= kLastEnum_SkColorType);
 }
 
-void SkImageInfo::unflatten(SkFlattenableReadBuffer& buffer) {
+void SkImageInfo::unflatten(SkReadBuffer& buffer) {
     fWidth = buffer.read32();
     fHeight = buffer.read32();
 
@@ -28,7 +29,7 @@
                     color_type_is_valid(fColorType));
 }
 
-void SkImageInfo::flatten(SkFlattenableWriteBuffer& buffer) const {
+void SkImageInfo::flatten(SkWriteBuffer& buffer) const {
     buffer.write32(fWidth);
     buffer.write32(fHeight);