fix warnings on Mac in src/images

Fix these class of warnings:
- unused functions
- unused locals
- sign mismatch
- missing function prototypes
- missing newline at end of file
- 64 to 32 bit truncation

The changes prefer to link in dead code in the debug build
with 'if (false)' than to comment it out, but trivial cases
are commented out or sometimes deleted if it appears to be
a copy/paste error.
Review URL: https://codereview.appspot.com/6299048

git-svn-id: http://skia.googlecode.com/svn/trunk@4179 2bbb7eff-a529-9590-31e7-b0007b416f81

src/images/SkFDStream.cpp

@@ -57,7 +57,7 @@ size_t SkFDStream::read(void* buffer, size_t size) {
 #endif
                 return 0;
             }
-            return size;
+            return (size_t) size;
         } else if (NULL == buffer) {        // skip
             off_t oldCurr = ::lseek(fFD, 0, SEEK_CUR);
             if (oldCurr < 0) {
@@ -74,7 +74,7 @@ size_t SkFDStream::read(void* buffer, size_t size) {
                 return 0;   // error;
             }
             // return the actual amount we skipped
-            return newCurr - oldCurr;
+            return (size_t) (newCurr - oldCurr);
         } else {                            // read
             ssize_t actual = ::read(fFD, buffer, size);
             // our API can't return an error, so we return 0

src/images/SkImageDecoder_libbmp.cpp

@@ -31,7 +31,7 @@ protected:
 DEFINE_DECODER_CREATOR(BMPImageDecoder);
 ///////////////////////////////////////////////////////////////////////////////
 
-SkImageDecoder* sk_libbmp_dfactory(SkStream* stream) {
+static SkImageDecoder* sk_libbmp_dfactory(SkStream* stream) {
     static const char kBmpMagic[] = { 'B', 'M' };
     
     size_t len = stream->getLength();

src/images/SkImageDecoder_libico.cpp

@@ -24,9 +24,11 @@ protected:
     virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode);
 };
 
+#if 0 // UNUSED
 SkImageDecoder* SkCreateICOImageDecoder() {
     return new SkICOImageDecoder;
 }
+#endif
 
 /////////////////////////////////////////////////////////////////////////////////////////
 
@@ -372,7 +374,7 @@ DEFINE_DECODER_CREATOR(ICOImageDecoder);
 
 #include "SkTRegistry.h"
 
-SkImageDecoder* sk_libico_dfactory(SkStream* stream) {
+static SkImageDecoder* sk_libico_dfactory(SkStream* stream) {
     // Check to see if the first four bytes are 0,0,1,0
     // FIXME: Is that required and sufficient?
     SkAutoMalloc autoMal(4);

src/images/SkImageDecoder_libjpeg.cpp

@@ -656,7 +656,7 @@ DEFINE_ENCODER_CREATOR(JPEGImageEncoder);
 
 #include "SkTRegistry.h"
 
-SkImageDecoder* sk_libjpeg_dfactory(SkStream* stream) {
+static SkImageDecoder* sk_libjpeg_dfactory(SkStream* stream) {
     static const unsigned char gHeader[] = { 0xFF, 0xD8, 0xFF };
     static const size_t HEADER_SIZE = sizeof(gHeader);
 

src/images/SkImageDecoder_wbmp.cpp

@@ -153,7 +153,7 @@ DEFINE_DECODER_CREATOR(WBMPImageDecoder);
 
 #include "SkTRegistry.h"
 
-SkImageDecoder* sk_wbmp_dfactory(SkStream* stream) {
+static SkImageDecoder* sk_wbmp_dfactory(SkStream* stream) {
     wbmp_head   head;
 
     if (head.init(stream)) {

src/images/SkJpegUtility.cpp

@@ -74,6 +74,7 @@ static boolean sk_resync_to_restart(j_decompress_ptr cinfo, int desired) {
 static void sk_term_source(j_decompress_ptr /*cinfo*/) {}
 
 
+#if 0 // UNUSED
 static void skmem_init_source(j_decompress_ptr cinfo) {
     skjpeg_source_mgr*  src = (skjpeg_source_mgr*)cinfo->src;
     src->next_input_byte = (const JOCTET*)src->fMemoryBase;
@@ -98,6 +99,7 @@ static boolean skmem_resync_to_restart(j_decompress_ptr cinfo, int desired) {
 }
 
 static void skmem_term_source(j_decompress_ptr /*cinfo*/) {}
+#endif
 
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -105,7 +107,7 @@ static void skmem_term_source(j_decompress_ptr /*cinfo*/) {}
 skjpeg_source_mgr::skjpeg_source_mgr(SkStream* stream, SkImageDecoder* decoder,
                                      bool ownStream) : fStream(stream) {
     fDecoder = decoder;
-    const void* baseAddr = stream->getMemoryBase();
+    // const void* baseAddr = stream->getMemoryBase();
     fMemoryBase = NULL;
     fUnrefStream = ownStream;
     fMemoryBaseSize = 0;