Make code path for bounds changes getting to renderer less brittle

content/content_browser.gypi

Index: content/content_browser.gypi
diff --git a/content/content_browser.gypi b/content/content_browser.gypi
index 1fc3c688523d5facc9631a1491f19083326aca08..a81434cda422f0d5ecbf9562e8f4dd4b4423aaf5 100644
--- a/content/content_browser.gypi
+++ b/content/content_browser.gypi
@@ -1159,6 +1159,10 @@
     'browser/web_contents/aura/image_window_delegate.h',
     'browser/web_contents/aura/shadow_layer_delegate.cc',
     'browser/web_contents/aura/shadow_layer_delegate.h',
+    'browser/web_contents/aura/constrained_windows_observer.cc',
+    'browser/web_contents/aura/constrained_windows_observer.h',
+    'browser/web_contents/aura/native_view_screen_bounds_observer.cc',
+    'browser/web_contents/aura/native_view_screen_bounds_observer.h',
     'browser/web_contents/aura/window_slider.cc',
     'browser/web_contents/aura/window_slider.h',
     'browser/web_contents/drag_utils_gtk.cc',
@@ -1383,6 +1387,11 @@
           },
         },
       },
+    }, { # 'OS!="win"'
+      'sources/': [
+        ['exclude', 'browser/web_contents/aura/constrained_windows_observer.cc'],
+        ['exclude', 'browser/web_contents/aura/constrained_windows_observer.h'],
+      ],
     }],
     ['toolkit_uses_gtk == 1', {
       'dependencies': [