Move the JPEG and PNG codecs from base/gfx to app/gfx/codec. Move the classes

into the gfx namespace.

Combine the PNGEncoder and PNGDecoder. There were separate when we had
different executables for the browser and renderer, and linked the encoder only
in one of them (which saved us some space used by libpng). This hasn't been the
case for years, so combining them (again) makes sense.

TEST=none
BUG=none
Review URL: http://codereview.chromium.org/243076

git-svn-id: http://src.chromium.org/svn/trunk/src/build@27930 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -480,7 +480,7 @@
           '-D_FILE_OFFSET_BITS=64',
         ],
         'cflags_cc': [
-          '-fno-rtti',
+          #'-fno-rtti',
           '-fno-threadsafe-statics',
         ],
         'ldflags': [