Clean up the functions in loadimage.h/cpp.

* Capitalize the function names to fit the style guide.
* Use explicit sizes in the function names to avoid any confusion about
  input or output sizes.
* Use explicit sized types in the functions to avoid potential issues on
  new platforms since a lot of bit-twiddling is used.
* Use size_t for all sizes.
* Use uint8_t for all binary data for input and output data so that pointer
  arithmetic is much easier.
* Move templated function definitions into an .inl file so that
  loadimage.h looks as clean as possible.

BUG=angle:665

Change-Id: Id7173ed66d9e1b7ee3261eea11e77d838cbd2951
Reviewed-on: https://chromium-review.googlesource.com/202590
Reviewed-by: Brandon Jones <bajones@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libGLESv2/formatutils.h b/src/libGLESv2/formatutils.h
index 692ab88..71d212c 100644
--- a/src/libGLESv2/formatutils.h
+++ b/src/libGLESv2/formatutils.h
@@ -14,16 +14,18 @@
 #include "libGLESv2/Caps.h"
 #include "libGLESv2/angletypes.h"
 
+#include <cstddef>
+
 typedef void (*MipGenerationFunction)(unsigned int sourceWidth, unsigned int sourceHeight, unsigned int sourceDepth,
                                       const unsigned char *sourceData, int sourceRowPitch, int sourceDepthPitch,
                                       unsigned char *destData, int destRowPitch, int destDepthPitch);
 
-typedef void (*LoadImageFunction)(int width, int height, int depth,
-                                  const void *input, unsigned int inputRowPitch, unsigned int inputDepthPitch,
-                                  void *output, unsigned int outputRowPitch, unsigned int outputDepthPitch);
+typedef void (*LoadImageFunction)(size_t width, size_t height, size_t depth,
+                                  const uint8_t *input, size_t inputRowPitch, size_t inputDepthPitch,
+                                  uint8_t *output, size_t outputRowPitch, size_t outputDepthPitch);
 
-typedef void (*InitializeTextureDataFunction)(int width, int height, int depth,
-                                              void *output, unsigned int outputRowPitch, unsigned int outputDepthPitch);
+typedef void (*InitializeTextureDataFunction)(size_t width, size_t height, size_t depth,
+                                              uint8_t *output, size_t outputRowPitch, size_t outputDepthPitch);
 
 typedef void (*ColorReadFunction)(const void *source, void *dest);
 typedef void (*ColorWriteFunction)(const void *source, void *dest);