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/effects/SkLayerRasterizer.cpp b/src/effects/SkLayerRasterizer.cpp
index ea5808c..6381c4d 100644
--- a/src/effects/SkLayerRasterizer.cpp
+++ b/src/effects/SkLayerRasterizer.cpp
@@ -9,7 +9,8 @@
 
 #include "SkLayerRasterizer.h"
 #include "SkDraw.h"
-#include "SkFlattenableBuffers.h"
+#include "SkReadBuffer.h"
+#include "SkWriteBuffer.h"
 #include "SkMask.h"
 #include "SkMaskFilter.h"
 #include "SkPaint.h"
@@ -143,7 +144,7 @@
     return true;
 }
 
-SkLayerRasterizer::SkLayerRasterizer(SkFlattenableReadBuffer& buffer)
+SkLayerRasterizer::SkLayerRasterizer(SkReadBuffer& buffer)
     : SkRasterizer(buffer), fLayers(sizeof(SkLayerRasterizer_Rec)) {
     int count = buffer.readInt();
 
@@ -156,7 +157,7 @@
     }
 }
 
-void SkLayerRasterizer::flatten(SkFlattenableWriteBuffer& buffer) const {
+void SkLayerRasterizer::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.writeInt(fLayers.count());