Eliminate SkFILE: it always is the same as FILE.

Review URL: https://codereview.chromium.org/1467533003
diff --git a/include/core/SkData.h b/include/core/SkData.h
index 28bf515..60a98e0 100644
--- a/include/core/SkData.h
+++ b/include/core/SkData.h
@@ -8,9 +8,10 @@
 #ifndef SkData_DEFINED
 #define SkData_DEFINED
 
+#include <stdio.h>
+
 #include "SkRefCnt.h"
 
-struct SkFILE;
 class SkStream;
 
 /**
@@ -119,13 +120,13 @@
     static SkData* NewFromFileName(const char path[]);
 
     /**
-     *  Create a new dataref from a SkFILE.
-     *  This does not take ownership of the SkFILE, nor close it.
-     *  The caller is free to close the SkFILE at its convenience.
-     *  The SkFILE must be open for reading only.
+     *  Create a new dataref from a stdio FILE.
+     *  This does not take ownership of the FILE, nor close it.
+     *  The caller is free to close the FILE at its convenience.
+     *  The FILE must be open for reading only.
      *  Returns NULL on failure.
      */
-    static SkData* NewFromFILE(SkFILE* f);
+    static SkData* NewFromFILE(FILE* f);
 
     /**
      *  Create a new dataref from a file descriptor.
diff --git a/include/core/SkOSFile.h b/include/core/SkOSFile.h
index 3ee3aa4..39a1646 100644
--- a/include/core/SkOSFile.h
+++ b/include/core/SkOSFile.h
@@ -12,9 +12,9 @@
 #ifndef SkOSFile_DEFINED
 #define SkOSFile_DEFINED
 
-#include "SkString.h"
+#include <stdio.h>
 
-struct SkFILE;
+#include "SkString.h"
 
 enum SkFILE_Flags {
     kRead_SkFILE_Flag   = 0x01,
@@ -27,30 +27,30 @@
 const static char SkPATH_SEPARATOR = '/';
 #endif
 
-SkFILE* sk_fopen(const char path[], SkFILE_Flags);
-void    sk_fclose(SkFILE*);
+FILE* sk_fopen(const char path[], SkFILE_Flags);
+void    sk_fclose(FILE*);
 
-size_t  sk_fgetsize(SkFILE*);
+size_t  sk_fgetsize(FILE*);
 /** Return true if the file could seek back to the beginning
 */
-bool    sk_frewind(SkFILE*);
+bool    sk_frewind(FILE*);
 
-size_t  sk_fread(void* buffer, size_t byteCount, SkFILE*);
-size_t  sk_fwrite(const void* buffer, size_t byteCount, SkFILE*);
+size_t  sk_fread(void* buffer, size_t byteCount, FILE*);
+size_t  sk_fwrite(const void* buffer, size_t byteCount, FILE*);
 
-char*   sk_fgets(char* str, int size, SkFILE* f);
+char*   sk_fgets(char* str, int size, FILE* f);
 
-void    sk_fflush(SkFILE*);
+void    sk_fflush(FILE*);
 
-bool    sk_fseek(SkFILE*, size_t);
-bool    sk_fmove(SkFILE*, long);
-size_t  sk_ftell(SkFILE*);
+bool    sk_fseek(FILE*, size_t);
+bool    sk_fmove(FILE*, long);
+size_t  sk_ftell(FILE*);
 
 /** Maps a file into memory. Returns the address and length on success, NULL otherwise.
  *  The mapping is read only.
  *  When finished with the mapping, free the returned pointer with sk_fmunmap.
  */
-void*   sk_fmmap(SkFILE* f, size_t* length);
+void*   sk_fmmap(FILE* f, size_t* length);
 
 /** Maps a file descriptor into memory. Returns the address and length on success, NULL otherwise.
  *  The mapping is read only.
@@ -64,12 +64,12 @@
 void    sk_fmunmap(const void* addr, size_t length);
 
 /** Returns true if the two point at the exact same filesystem object. */
-bool    sk_fidentical(SkFILE* a, SkFILE* b);
+bool    sk_fidentical(FILE* a, FILE* b);
 
 /** Returns the underlying file descriptor for the given file.
  *  The return value will be < 0 on failure.
  */
-int     sk_fileno(SkFILE* f);
+int     sk_fileno(FILE* f);
 
 /** Returns true if something (file, directory, ???) exists at this path,
  *  and has the specified access flags.
@@ -80,7 +80,7 @@
 bool    sk_isdir(const char *path);
 
 // Have we reached the end of the file?
-int sk_feof(SkFILE *);
+int sk_feof(FILE *);
 
 
 // Create a new directory at this path; returns true if successful.
diff --git a/include/core/SkStream.h b/include/core/SkStream.h
index 6767778..2279f9f 100644
--- a/include/core/SkStream.h
+++ b/include/core/SkStream.h
@@ -224,8 +224,6 @@
 #include "SkString.h"
 #include <stdio.h>
 
-struct SkFILE;
-
 /** A stream that wraps a C FILE* file stream. */
 class SK_API SkFILEStream : public SkStreamAsset {
 public:
@@ -271,7 +269,7 @@
     const void* getMemoryBase() override;
 
 private:
-    SkFILE*     fFILE;
+    FILE*     fFILE;
     SkString    fName;
     Ownership   fOwnership;
     // fData is lazilly initialized when needed.
@@ -364,7 +362,7 @@
     size_t bytesWritten() const override;
 
 private:
-    SkFILE* fFILE;
+    FILE* fFILE;
 
     typedef SkWStream INHERITED;
 };