gnu: qt: Remove the sources of qtwebengine.

* gnu/packages/qt.scm (qt)[source]: Add snippet to remove the qtwebengine
  code, which was already not built anymore, and drop one patch used
  previously only for qtwebengine.
  [arguments]: Drop the configuration flag "-skip qtwebengine", since
  deleted modules cannot be skipped.
* gnu/packages/patches/qt5-runpath.patch: Delete file.
* gnu-system.am (dist_patch_DATA): Unregister patch.

Partially fixes <http://bugs.gnu.org/21288>.

gnu-system.am

@@ -611,7 +611,6 @@ dist_patch_DATA =						\
   gnu/packages/patches/python2-pygobject-2-gi-info-type-error-domain.patch \
   gnu/packages/patches/qemu-CVE-2015-6855.patch			\
   gnu/packages/patches/qt4-ldflags.patch			\
-  gnu/packages/patches/qt5-runpath.patch			\
   gnu/packages/patches/ratpoison-shell.patch			\
   gnu/packages/patches/readline-link-ncurses.patch		\
   gnu/packages/patches/ripperx-missing-file.patch		\

gnu/packages/patches/qt5-runpath.patch

@@ -1,27 +0,0 @@
-Allow the use of DT_RUNPATH.  This fixes a bug whereby libQt5WebEngineCore.so
-ends up having an empty RUNPATH.
-
-
-diff -u -r qt-everywhere-opensource-src-5.5.0.orig/qtwebengine/src/3rdparty/chromium/build/common.gypi qt-everywhere-opensource-src-5.5.0/qtwebengine/src/3rdparty/chromium/build/common.gypi
---- qt-everywhere-opensource-src-5.5.0.orig/qtwebengine/src/3rdparty/chromium/build/common.gypi	2015-06-29 22:09:36.000000000 +0200
-+++ qt-everywhere-opensource-src-5.5.0/qtwebengine/src/3rdparty/chromium/build/common.gypi	2015-07-25 15:32:57.999411191 +0200
-@@ -4448,19 +4448,6 @@
-               '-B<!(cd <(DEPTH) && pwd -P)/<(binutils_dir)',
-             ],
-           }],
--          # Some binutils 2.23 releases may or may not have new dtags enabled,
--          # but they are all compatible with --disable-new-dtags,
--          # because the new dynamic tags are not created by default.
--          ['binutils_version>=223', {
--            # Newer binutils don't set DT_RPATH unless you disable "new" dtags
--            # and the new DT_RUNPATH doesn't work without --no-as-needed flag.
--            # FIXME(mithro): Figure out the --as-needed/--no-as-needed flags
--            # inside this file to allow usage of --no-as-needed and removal of
--            # this flag.
--            'ldflags': [
--              '-Wl,--disable-new-dtags',
--            ],
--          }],
-           ['gcc_version>=47 and clang==0', {
-             'target_conditions': [
-               ['_toolset=="target"', {

gnu/packages/qt.scm

@@ -108,7 +108,16 @@ X11 (yet).")
              (sha256
                (base32
                  "1by2l8wxbqwvs7anb5ggmqhn2cfmhyw3a23bp1yyd240rdpa38ky"))
-             (patches (list (search-patch "qt5-runpath.patch")))))
+             (modules '((guix build utils)))
+             (snippet
+              ;; Remove qtwebengine, which relies on a bundled copy of
+              ;; chromium. Not only does it fail compilation in qt 5.5:
+              ;;    3rdparty/chromium/ui/gfx/codec/jpeg_codec.cc:362:10:
+              ;;    error: cannot convert ‘bool’ to ‘boolean’ in return
+              ;; it might also pose security problems.
+              ;; Alternatively, we could use the "-skip qtwebengine"
+              ;; configuration option.
+              '(delete-file-recursively "qtwebengine"))))
     (build-system gnu-build-system)
     (propagated-inputs
      `(("mesa" ,mesa)))
@@ -158,8 +167,6 @@ X11 (yet).")
      `(("bison" ,bison)
        ("flex" ,flex)
        ("gperf" ,gperf)
-       ;; Ninja is only needed for the disabled qtwebengine
-;;        ("ninja" ,ninja)
        ("perl" ,perl)
        ("pkg-config" ,pkg-config)
        ("python" ,python-2)
@@ -175,14 +182,6 @@ X11 (yet).")
                 (("/bin/pwd") (which "pwd")))
               (substitute* "qtbase/src/corelib/global/global.pri"
                 (("/bin/ls") (which "ls")))
-              ;; commented out since qtwebengine is not built, but left in
-              ;; for reference
-;;               (substitute* "qtwebengine/src/3rdparty/chromium/build/common.gypi"
-;;                 (("/bin/echo") (which "echo")))
-;;               (substitute* "qtwebengine/src/3rdparty/chromium/third_party/\
-;; WebKit/Source/build/scripts/scripts.gypi"
-;;                 (("/usr/bin/gcc") (which "gcc")))
-;;               (setenv "NINJA_PATH" (which "ninja"))
               ;; do not pass "--enable-fast-install", which makes the
               ;; configure process fail
               (zero? (system*
@@ -196,12 +195,6 @@ X11 (yet).")
                       "-openssl-linked"
                       ;; explicitly link with dbus instead of dlopening it
                       "-dbus-linked"
-                      ;; drop chromium module (qtwebengine); it fails
-                      ;; compilation in qt 5.5:
-                      ;; 3rdparty/chromium/ui/gfx/codec/jpeg_codec.cc:362:10:
-                      ;; error: cannot convert ‘bool’ to ‘boolean’ in return
-                      ;; and might pose security problems.
-                      "-skip" "qtwebengine"
                       ;; drop special machine instructions not supported
                       ;; on all instances of the target
                       ,@(if (string-prefix? "x86_64"