roll libyuv to r1038 from r1035 to add gyp define that makes jpeg optional.

DEPS

 # This file is automatically processed to create .DEPS.git which is the file
 # that gclient uses under git.
 #
 # See http://code.google.com/p/chromium/wiki/UsingGit
 #
 # To test manually, run:
 #   python tools/deps2git/deps2git.py -o .DEPS.git -w <gclientdir>
 # where <gcliendir> is the absolute path to the directory containing the
 # .gclient file (the parent of "src").
 #
@@ skipping 248 matching lines @@
 
   "src/third_party/jsoncpp/source/include":
     (Var("sourceforge_url") % {"repo": "jsoncpp"}) +
         "/trunk/jsoncpp/include@" + Var("jsoncpp_revision"),
 
   "src/third_party/jsoncpp/source/src/lib_json":
     (Var("sourceforge_url") % {"repo": "jsoncpp"}) +
         "/trunk/jsoncpp/src/lib_json@" + Var("jsoncpp_revision"),
 
   "src/third_party/libyuv":
-    (Var("googlecode_url") % "libyuv") + "/trunk@1035",
+    (Var("googlecode_url") % "libyuv") + "/trunk@1038",
 
   "src/third_party/smhasher/src":
     (Var("googlecode_url") % "smhasher") + "/trunk@152",
 
   "src/third_party/libaddressinput/src/cpp":
     (Var("googlecode_url") % "libaddressinput") + "/trunk/cpp@" +
         Var("libaddressinput_revision"),
   "src/third_party/libaddressinput/src/testdata":
     (Var("googlecode_url") % "libaddressinput") + "/trunk/testdata@" +
         Var("libaddressinput_revision"),
@@ skipping 524 matching lines @@
                 "src/third_party/apache-win32",
     ],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     "name": "gyp",
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
 ]