Do IWYU for content_export.h

Headers that use CONTENT_EXPORT should include content_export.h.

Change-Id: I66b65c9c3a963d1f4677172b12ef0966448e1609
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3282640
Commit-Queue: Lei Zhang <[email protected]>
Auto-Submit: Lei Zhang <[email protected]>
Reviewed-by: Avi Drissman <[email protected]>
Owners-Override: Avi Drissman <[email protected]>
Cr-Commit-Position: refs/heads/main@{#942394}
diff --git a/content/browser/host_zoom_map_impl.h b/content/browser/host_zoom_map_impl.h
index 4be66727..df9b8143 100644
--- a/content/browser/host_zoom_map_impl.h
+++ b/content/browser/host_zoom_map_impl.h
@@ -12,6 +12,7 @@
 
 #include "base/compiler_specific.h"
 #include "base/task/sequenced_task_runner_helpers.h"
+#include "content/common/content_export.h"
 #include "content/public/browser/host_zoom_map.h"
 
 namespace content {