Do not consolidate data in BMPImageDecoder

Source/platform/image-decoders/bmp/BMPImageDecoder.cpp

Index: Source/platform/image-decoders/bmp/BMPImageDecoder.cpp
diff --git a/Source/platform/image-decoders/bmp/BMPImageDecoder.cpp b/Source/platform/image-decoders/bmp/BMPImageDecoder.cpp
index f08295962ff2f8a2c87379fa46d3d5a2a71b6e01..17d52fbe8bd7b564342433fcdd2a4d5113d136c2 100644
--- a/Source/platform/image-decoders/bmp/BMPImageDecoder.cpp
+++ b/Source/platform/image-decoders/bmp/BMPImageDecoder.cpp
@@ -31,6 +31,7 @@
 #include "config.h"
 #include "platform/image-decoders/bmp/BMPImageDecoder.h"
 
+#include "platform/image-decoders/FastSharedBufferReader.h"
 #include "wtf/PassOwnPtr.h"
 
 namespace blink {
@@ -100,8 +101,12 @@ bool BMPImageDecoder::processFileHeader(size_t& imgDataOffset)
     ASSERT(!m_decodedOffset);
     if (m_data->size() < sizeOfFileHeader)
         return false;
-    const uint16_t fileType = (m_data->data()[0] << 8) | static_cast<uint8_t>(m_data->data()[1]);
-    imgDataOffset = readUint32(10);
+
+    char buffer[sizeOfFileHeader];
+    FastSharedBufferReader fastReader(m_data);
+    const char* fileHeader = fastReader.getConsecutiveData(0, sizeOfFileHeader, buffer);
+    const uint16_t fileType = (fileHeader[0] << 8) | static_cast<uint8_t>(fileHeader[1]);
+    imgDataOffset = BMPImageReader::readUint32(&fileHeader[10]);
     m_decodedOffset = sizeOfFileHeader;
 
     // See if this is a bitmap filetype we understand.