Delete the GTK+ port of Chrome.

content/content_shell.gypi

Index: content/content_shell.gypi
diff --git a/content/content_shell.gypi b/content/content_shell.gypi
index c84d485346c78c132d3140d8c8dc591cdef5d2fb..e319a372e34e92d275810017153aa4fca4790f7e 100644
--- a/content/content_shell.gypi
+++ b/content/content_shell.gypi
@@ -108,9 +108,7 @@
         'shell/browser/shell_devtools_frontend.h',
         'shell/browser/shell_download_manager_delegate.cc',
         'shell/browser/shell_download_manager_delegate.h',
-        'shell/browser/shell_gtk.cc',
         'shell/browser/shell.h',
-        'shell/browser/shell_javascript_dialog_gtk.cc',
         'shell/browser/shell_javascript_dialog.h',
         'shell/browser/shell_javascript_dialog_mac.mm',
         'shell/browser/shell_javascript_dialog_manager.cc',
@@ -119,7 +117,6 @@
         'shell/browser/shell_layout_tests_android.cc',
         'shell/browser/shell_layout_tests_android.h',
         'shell/browser/shell_login_dialog.cc',
-        'shell/browser/shell_login_dialog_gtk.cc',
         'shell/browser/shell_login_dialog.h',
         'shell/browser/shell_login_dialog_mac.mm',
         'shell/browser/shell_mac.mm',
@@ -144,7 +141,6 @@
         'shell/browser/shell_views.cc',
         'shell/browser/shell_web_contents_view_delegate_android.cc',
         'shell/browser/shell_web_contents_view_delegate_creator.h',
-        'shell/browser/shell_web_contents_view_delegate_gtk.cc',
         'shell/browser/shell_web_contents_view_delegate.h',
         'shell/browser/shell_web_contents_view_delegate_mac.mm',
         'shell/browser/shell_web_contents_view_delegate_win.cc',
@@ -321,9 +317,6 @@
             '../ui/base/strings/ui_strings.gyp:ui_strings',
             '../ui/events/events.gyp:events',
           ],
-          'sources/': [
-            ['exclude', 'shell/browser/shell_gtk.cc'],
-          ],
           'conditions': [
             ['toolkit_views==1', {
               'dependencies': [
@@ -570,11 +563,6 @@
             '../sandbox/sandbox.gyp:sandbox',
           ],
         }],  # OS=="win" or toolkit_uses_gtk == 1
-        ['toolkit_uses_gtk == 1', {
-          'dependencies': [
-            '<(DEPTH)/build/linux/system.gyp:gtk',
-          ],
-        }],  # toolkit_uses_gtk
         ['OS=="mac"', {
           'product_name': '<(content_shell_product_name)',
           'dependencies!': [