Remove redundant reading and writing of data about SharedBuffer.

third_party/WebKit/Source/platform/image-decoders/SegmentReader.h

Index: third_party/WebKit/Source/platform/image-decoders/SegmentReader.h
diff --git a/third_party/WebKit/Source/platform/image-decoders/SegmentReader.h b/third_party/WebKit/Source/platform/image-decoders/SegmentReader.h
index 8fc14e7004f6c02f9de5d9a295f601f9b0ffdba5..3b409caea1f8c09e8d3cd419eca24ff15236b873 100644
--- a/third_party/WebKit/Source/platform/image-decoders/SegmentReader.h
+++ b/third_party/WebKit/Source/platform/image-decoders/SegmentReader.h
@@ -6,6 +6,7 @@
 #define SegmentReader_h
 
 #include "platform/SharedBuffer.h"
+#include "platform/SharedBufferStep.h"
 #include "platform/wtf/Noncopyable.h"
 #include "platform/wtf/PassRefPtr.h"
 #include "platform/wtf/ThreadSafeRefCounted.h"
@@ -37,6 +38,9 @@ class PLATFORM_EXPORT SegmentReader
   static PassRefPtr<SegmentReader> CreateFromSharedBuffer(
       PassRefPtr<SharedBuffer>);
 
+  static PassRefPtr<SegmentReader> CreateFromSharedBufferStep(
+      PassRefPtr<SharedBufferStep>);
+
   // These versions use thread-safe input, so they are always thread-safe.
   static PassRefPtr<SegmentReader> CreateFromSkData(sk_sp<SkData>);
   static PassRefPtr<SegmentReader> CreateFromSkROBuffer(sk_sp<SkROBuffer>);