diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/core/SkBuffer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/core/SkBuffer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,170 @@
+
+/*
+ * Copyright 2006 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef SkBuffer_DEFINED
+#define SkBuffer_DEFINED
+
+#include "SkScalar.h"
+
+/** \class SkRBuffer
+
+    Light weight class for reading data from a memory block.
+    The RBuffer is given the buffer to read from, with either a specified size
+    or no size (in which case no range checking is performed). It is iillegal
+    to attempt to read a value from an empty RBuffer (data == null).
+*/
+class SkRBuffer : SkNoncopyable {
+public:
+    SkRBuffer() : fData(0), fPos(0), fStop(0) {}
+    /** Initialize RBuffer with a data pointer, but no specified length.
+        This signals the RBuffer to not perform range checks during reading.
+    */
+    SkRBuffer(const void* data) {
+        fData = (const char*)data;
+        fPos = (const char*)data;
+        fStop = 0;  // no bounds checking
+    }
+    /** Initialize RBuffer with a data point and length.
+    */
+    SkRBuffer(const void* data, size_t size) {
+        SkASSERT(data != 0 || size == 0);
+        fData = (const char*)data;
+        fPos = (const char*)data;
+        fStop = (const char*)data + size;
+    }
+
+    virtual ~SkRBuffer() { }
+
+    /** Return the number of bytes that have been read from the beginning
+        of the data pointer.
+    */
+    size_t  pos() const { return fPos - fData; }
+    /** Return the total size of the data pointer. Only defined if the length was
+        specified in the constructor or in a call to reset().
+    */
+    size_t  size() const { return fStop - fData; }
+    /** Return true if the buffer has read to the end of the data pointer.
+        Only defined if the length was specified in the constructor or in a call
+        to reset(). Always returns true if the length was not specified.
+    */
+    bool    eof() const { return fPos >= fStop; }
+
+    /** Read the specified number of bytes from the data pointer. If buffer is not
+        null, copy those bytes into buffer.
+    */
+    virtual bool read(void* buffer, size_t size) {
+        if (size) {
+            this->readNoSizeCheck(buffer, size);
+        }
+        return true;
+    }
+
+    const void* skip(size_t size); // return start of skipped data
+    size_t  skipToAlign4();
+
+    bool readPtr(void** ptr) { return read(ptr, sizeof(void*)); }
+    bool readScalar(SkScalar* x) { return read(x, 4); }
+    bool readU32(uint32_t* x) { return read(x, 4); }
+    bool readS32(int32_t* x) { return read(x, 4); }
+    bool readU16(uint16_t* x) { return read(x, 2); }
+    bool readS16(int16_t* x) { return read(x, 2); }
+    bool readU8(uint8_t* x) { return read(x, 1); }
+    bool readBool(bool* x) {
+        uint8_t u8;
+        if (this->readU8(&u8)) {
+            *x = (u8 != 0);
+            return true;
+        }
+        return false;
+    }
+
+protected:
+    void    readNoSizeCheck(void* buffer, size_t size);
+
+    const char* fData;
+    const char* fPos;
+    const char* fStop;
+};
+
+/** \class SkRBufferWithSizeCheck
+
+    Same as SkRBuffer, except that a size check is performed before the read operation and an
+    error is set if the read operation is attempting to read past the end of the data.
+*/
+class SkRBufferWithSizeCheck : public SkRBuffer {
+public:
+    SkRBufferWithSizeCheck(const void* data, size_t size) : SkRBuffer(data, size), fError(false) {}
+
+    /** Read the specified number of bytes from the data pointer. If buffer is not
+        null and the number of bytes to read does not overflow this object's data,
+        copy those bytes into buffer.
+    */
+    virtual bool read(void* buffer, size_t size) SK_OVERRIDE;
+
+    /** Returns whether or not a read operation attempted to read past the end of the data.
+    */
+    bool isValid() const { return !fError; }
+private:
+    bool fError;
+};
+
+/** \class SkWBuffer
+
+    Light weight class for writing data to a memory block.
+    The WBuffer is given the buffer to write into, with either a specified size
+    or no size, in which case no range checking is performed. An empty WBuffer
+    is legal, in which case no data is ever written, but the relative pos()
+    is updated.
+*/
+class SkWBuffer : SkNoncopyable {
+public:
+    SkWBuffer() : fData(0), fPos(0), fStop(0) {}
+    SkWBuffer(void* data) { reset(data); }
+    SkWBuffer(void* data, size_t size) { reset(data, size); }
+
+    void reset(void* data) {
+        fData = (char*)data;
+        fPos = (char*)data;
+        fStop = 0;  // no bounds checking
+    }
+
+    void reset(void* data, size_t size) {
+        SkASSERT(data != 0 || size == 0);
+        fData = (char*)data;
+        fPos = (char*)data;
+        fStop = (char*)data + size;
+    }
+
+    size_t  pos() const { return fPos - fData; }
+    void*   skip(size_t size); // return start of skipped data
+
+    void write(const void* buffer, size_t size) {
+        if (size) {
+            this->writeNoSizeCheck(buffer, size);
+        }
+    }
+
+    size_t  padToAlign4();
+
+    void    writePtr(const void* x) { this->writeNoSizeCheck(&x, sizeof(x)); }
+    void    writeScalar(SkScalar x) { this->writeNoSizeCheck(&x, 4); }
+    void    write32(int32_t x) { this->writeNoSizeCheck(&x, 4); }
+    void    write16(int16_t x) { this->writeNoSizeCheck(&x, 2); }
+    void    write8(int8_t x) { this->writeNoSizeCheck(&x, 1); }
+    void    writeBool(bool x) { this->write8(x); }
+
+private:
+    void    writeNoSizeCheck(const void* buffer, size_t size);
+
+    char* fData;
+    char* fPos;
+    char* fStop;
+};
+
+#endif