WIP: Added support for giflib, updated jpeg and png

DEPS

Index: DEPS
diff --git a/DEPS b/DEPS
index 15917a967bbe2b5ca0993349fa3b980d7ec244dd..e369f804a576a33967ba4cec1d61961b7c7ec2d0 100644
--- a/DEPS
+++ b/DEPS
@@ -6,7 +6,6 @@ deps = {
   "common": "https://skia.googlesource.com/common.git@d7c2e2b9464e70e0f3847a330b930d008dc8c8db",
 
   # There is some duplication here that might be worth cleaning up:
-  #   - both Android and ChromeOS pull the same giflib;
   #   - can use use our existing t_p/e/libjpeg instead of pulling it for Android?
 
   "third_party/externals/angle2"  : "https://chromium.googlesource.com/angle/angle.git@c415283b2bcd786e1a8c55c19ef3511eb2b3928c",
@@ -20,13 +19,12 @@ deps = {
   "third_party/externals/zlib"    : "https://chromium.googlesource.com/chromium/src/third_party/zlib@4ba7cdd0e7bf49d671645264f839838fc56e1492",
   # NOTE: If we update libpng, we may need to update the generated file at third_party/libpng/pnglibconf.h
   "third_party/externals/libpng"  : "git://git.code.sf.net/p/libpng/code@070a616b8275277e18ef8ee91e2ca23f7bdc67d5",
+  "third_party/externals/giflib"  : "https://android.googlesource.com/platform/external/giflib.git@android-5.1.0_r3",
 
-  "platform_tools/android/third_party/externals/expat" : "https://android.googlesource.com/platform/external/expat.git@android-4.2.2_r1.2",
-  "platform_tools/android/third_party/externals/gif" : "https://android.googlesource.com/platform/external/giflib.git@android-4.2.2_r1.2",
-  "platform_tools/android/third_party/externals/jpeg" : "https://android.googlesource.com/platform/external/jpeg.git@ef1b83013e7814622a9d11579878d342e84580b7",
+  "platform_tools/android/third_party/externals/expat" : "https://android.googlesource.com/platform/external/expat.git@android-5.1.0_r3",
+  "platform_tools/android/third_party/externals/jpeg" : "https://android.googlesource.com/platform/external/jpeg.git@android-5.1.0_r3",
   "platform_tools/android/third_party/externals/png" : "https://android.googlesource.com/platform/external/libpng.git@android-4.2.2_r1.2",
 
-  "platform_tools/chromeos/third_party/externals/gif" : "https://android.googlesource.com/platform/external/giflib.git@android-4.2.2_r1.2",
   "platform_tools/chromeos/toolchain/src/third_party/chromite": "https://chromium.googlesource.com/chromiumos/chromite.git@d6a4c7e0ee4d53ddc5238dbddfc0417796a70e54",
   "platform_tools/chromeos/toolchain/src/third_party/pyelftools": "https://chromium.googlesource.com/chromiumos/third_party/pyelftools.git@bdc1d380acd88d4bfaf47265008091483b0d614e",