Re-implement the screensaver to use WebView instead of ExtensionDialogHost.

ash/ash.gyp

Index: ash/ash.gyp
diff --git a/ash/ash.gyp b/ash/ash.gyp
index 34a97b6083c34fa6f9590bce768bc6bc7f081f83..d62fd60932ab98d50233331be1090e3dadd5a613 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -18,6 +18,8 @@
         '../base/base.gyp:base_i18n',
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
         '../build/temp_gyp/googleurl.gyp:googleurl',
+        '../content/content.gyp:content',
+        '../content/content.gyp:content_browser',
         '../net/net.gyp:net',
         '../skia/skia.gyp:skia',
         '../third_party/icu/icu.gyp:icui18n',
@@ -111,6 +113,8 @@
         'monitor/secondary_monitor_view.h',
         'screen_ash.cc',
         'screen_ash.h',
+        'screensaver/screensaver_view.cc',
+        'screensaver/screensaver_view.h',
         'screenshot_delegate.h',
         'shell.cc',
         'shell.h',
@@ -317,6 +321,11 @@
         '../base/base.gyp:base',
         '../base/base.gyp:test_support_base',
         '../chrome/chrome_resources.gyp:packed_resources',
+        '../content/content.gyp:content',
+        '../content/content.gyp:content_browser',
+        '../content/content.gyp:test_support_content',
+        '../ipc/ipc.gyp:test_support_ipc',
+        '../net/net.gyp:net_test_support',
         '../build/temp_gyp/googleurl.gyp:googleurl',
         '../skia/skia.gyp:skia',
         '../testing/gtest.gyp:gtest',
@@ -349,6 +358,9 @@
         'launcher/launcher_unittest.cc',
         'launcher/launcher_view_unittest.cc',
         'monitor/multi_monitor_manager_unittest.cc',
+        'screensaver/screensaver_view_unittest.cc',
+        'screensaver/test_webview.h',
+        'screensaver/test_webview.cc',
         'shell_unittest.cc',
         'test/ash_test_base.cc',
         'test/ash_test_base.h',