Make `getComputedStyle` return the correct style for collapsed <img> elements.

third_party/WebKit/LayoutTests/http/tests/subresource_filter/picture-disallowed.html

Index: third_party/WebKit/LayoutTests/http/tests/subresource_filter/picture-disallowed.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/subresource_filter/picture-disallowed.html b/third_party/WebKit/LayoutTests/http/tests/subresource_filter/picture-disallowed.html
index b7b0346abea958a346324fda7c9f427423fe6de0..96ddb45a1010aa1782168dde66410069f70c21a1 100644
--- a/third_party/WebKit/LayoutTests/http/tests/subresource_filter/picture-disallowed.html
+++ b/third_party/WebKit/LayoutTests/http/tests/subresource_filter/picture-disallowed.html
@@ -35,6 +35,8 @@ async_test(t => {
   i.onload = t.step_func_done(_ => {
     assert_equals(i.clientWidth, 100, "Images that are not disallowed should be displayed at their natural width.");
     assert_equals(i.clientHeight, 100, "Images that are not disallowed should be displayed at their natural height.");
+    let style = window.getComputedStyle(i);
+    assert_equals(style.display, "inline", "Images that are not disallowed should be display:inline");
   });
   document.body.append(p);
 }, "Images whose selected source URL is not disallowed should still be displayed as normal.");
@@ -48,6 +50,8 @@ async_test(t => {
     assert_equals(i.clientHeight, 0, "Images that are disallowed should be collapsed.");
     assert_equals(i.naturalWidth, 0, "Images that are disallowed should not be loaded.");
     assert_equals(i.naturalHeight, 0, "Images that are disallowed should not be loaded.");
+    let style = window.getComputedStyle(i);
+    assert_equals(style.display, "none", "Images that are disallowed should be set to display:none");
   });
   document.body.append(p);
 }, "Images whose selected source URL is disallowed should not be loaded and should be collapsed in the layout.");