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/SkPathHeap.h b/src/core/SkPathHeap.h
index 095e84a..e3b0f7a 100644
--- a/src/core/SkPathHeap.h
+++ b/src/core/SkPathHeap.h
@@ -13,15 +13,15 @@
 #include "SkTDArray.h"
 
 class SkPath;
-class SkFlattenableReadBuffer;
-class SkFlattenableWriteBuffer;
+class SkReadBuffer;
+class SkWriteBuffer;
 
 class SkPathHeap : public SkRefCnt {
 public:
     SK_DECLARE_INST_COUNT(SkPathHeap)
 
     SkPathHeap();
-    SkPathHeap(SkFlattenableReadBuffer&);
+    SkPathHeap(SkReadBuffer&);
     virtual ~SkPathHeap();
 
     /** Copy the path into the heap, and return the new total number of paths.
@@ -36,7 +36,7 @@
         return *fPaths[index];
     }
 
-    void flatten(SkFlattenableWriteBuffer&) const;
+    void flatten(SkWriteBuffer&) const;
 
 private:
     // we store the paths in the heap (placement new)