Remove all uses of toolkit_use_gtk in the gyp files.

chrome/chrome_tests.gypi

Index: chrome/chrome_tests.gypi
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index cafb5010b5b82d3c88d46a193af3edf34daa81ff..233333ce03e5eabbab7905f7db83de853de0bff4 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -151,17 +151,6 @@
             '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
           ],
         }],
-        ['toolkit_uses_gtk == 1', {
-          'dependencies': [
-            '../build/linux/system.gyp:gtk',
-          ],
-        }, {
-          'sources!': [
-            'browser/notifications/desktop_notifications_unittest.cc',
-            'browser/notifications/desktop_notifications_unittest.h',
-            'browser/notifications/notification_browsertest.cc',
-          ]
-        }],
         ['OS=="linux" and use_aura==1', {
           # TODO(gbillock): aura linux does not support the automation for
           # SendMouseMoveNotifyWhenDone
@@ -169,7 +158,7 @@
             'browser/ui/views/toolbar/toolbar_button_test.cc',
           ],
         }],
-        ['toolkit_uses_gtk == 1 or chromeos==1 or (OS=="linux" and use_aura==1)', {
+        ['OS=="linux"', {
           'dependencies': [
             '../build/linux/system.gyp:ssl',
           ],
@@ -1791,7 +1780,7 @@
             'app/chrome_version.rc.version',
           ],
         }],
-        ['toolkit_uses_gtk == 1 or chromeos==1 or (OS=="linux" and use_aura==1)', {
+        ['OS=="linux"', {
           'dependencies': [
             '../build/linux/system.gyp:ssl',
           ],
@@ -2093,7 +2082,7 @@
             '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
           ],
         }],
-        ['toolkit_uses_gtk == 1 or chromeos==1 or (OS=="linux" and use_aura==1)', {
+        ['OS=="linux"', {
           'dependencies': [
             '../build/linux/system.gyp:ssl',
           ],
@@ -2318,7 +2307,7 @@
         'browser/sync/test/integration/two_client_typed_urls_sync_test.cc',
       ],
       'conditions': [
-        ['toolkit_uses_gtk == 1 or chromeos==1 or (OS=="linux" and use_aura==1)', {
+        ['OS=="linux"', {
           'dependencies': [
             '../build/linux/system.gyp:ssl',
           ],
@@ -2423,7 +2412,7 @@
         'test/data/resource.rc',
       ],
       'conditions': [
-        ['toolkit_uses_gtk == 1 or chromeos==1 or (OS=="linux" and use_aura==1)', {
+        ['OS=="linux"', {
           'dependencies': [
             '../build/linux/system.gyp:ssl',
           ],