Revert of Do not consolidate data in BMPImageDecoder

Source/platform/image-decoders/FastSharedBufferReader.cpp

Index: Source/platform/image-decoders/FastSharedBufferReader.cpp
diff --git a/Source/platform/image-decoders/FastSharedBufferReader.cpp b/Source/platform/image-decoders/FastSharedBufferReader.cpp
index 63024c9eb091e8c0c5a502c9f566bb41dfaa1669..ef4d5717170b0f5e2c3eb9ca325810de9c892390 100644
--- a/Source/platform/image-decoders/FastSharedBufferReader.cpp
+++ b/Source/platform/image-decoders/FastSharedBufferReader.cpp
@@ -41,16 +41,6 @@ FastSharedBufferReader::FastSharedBufferReader(PassRefPtr<SharedBuffer> data)
 {
 }
 
-void FastSharedBufferReader::setData(PassRefPtr<SharedBuffer> data)
-{
-    if (data == m_data)
-        return;
-    m_data = data;
-    m_segment = 0;
-    m_segmentLength = 0;
-    m_dataPosition = 0;
-}
-
 const char* FastSharedBufferReader::getConsecutiveData(size_t dataPosition, size_t length, char* buffer) const
 {
     RELEASE_ASSERT(dataPosition + length <= m_data->size());