Fix page zoom to be frame-centric for out-of-process frames.

content/browser/loader/async_resource_handler.cc

Index: content/browser/loader/async_resource_handler.cc
diff --git a/content/browser/loader/async_resource_handler.cc b/content/browser/loader/async_resource_handler.cc
index 599767b01c1292ee6c3e7360492d120262fe7a5b..0d4356f7e513878db5f0a8700eeec86826febba3 100644
--- a/content/browser/loader/async_resource_handler.cc
+++ b/content/browser/loader/async_resource_handler.cc
@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <vector>
 
+#include "base/bind.h"
 #include "base/command_line.h"
 #include "base/containers/hash_tables.h"
 #include "base/debug/alias.h"
@@ -26,6 +27,7 @@
 #include "content/browser/resource_context_impl.h"
 #include "content/common/resource_messages.h"
 #include "content/common/view_messages.h"
+#include "content/public/browser/render_view_host.h"
 #include "content/public/browser/resource_dispatcher_host_delegate.h"
 #include "content/public/common/content_features.h"
 #include "content/public/common/resource_response.h"
@@ -314,6 +316,33 @@ bool AsyncResourceHandler::OnRequestRedirected(
       GetRequestID(), redirect_info, response->head));
 }
 
+namespace {
+
+// Defined here to be close to OnResponseStarted(), which is the only caller.
+void SetZoomLevelForViewFromWebContents(
+    ResourceRequestInfo::WebContentsGetter request_web_contents_getter,
+    int render_process_id,
+    int render_view_id,
+    const GURL request_url) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  WebContents* web_contents = request_web_contents_getter.Run();
+  if (!web_contents)
+    return;
+
+  double zoom_level = HostZoomMap::GetZoomLevel(web_contents);
+
+  RenderViewHost* render_view_host =
+      RenderViewHost::FromID(render_process_id, render_view_id);
+  if (!render_view_host)
+    return;
+
+  render_view_host->Send(new ViewMsg_SetZoomLevelForLoadingURL(
+      render_view_id, request_url, zoom_level));
+}
+
+}  // namespace anonymous
+
 bool AsyncResourceHandler::OnResponseStarted(ResourceResponse* response,
                                              bool* defer) {
   // For changes to the main frame, inform the renderer of the new URL's
@@ -357,6 +386,18 @@ bool AsyncResourceHandler::OnResponseStarted(ResourceResponse* response,
 
     info->filter()->Send(new ViewMsg_SetZoomLevelForLoadingURL(
         render_view_id, request_url, zoom_level));
+  } else if (info->GetResourceType() == RESOURCE_TYPE_SUB_FRAME &&
+             host_zoom_map) {
+    // Sub-frames should use the zoom level of their web-contents, regardless of
+    // their URL. We must access the WebContents on the UI thread.
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(
+            &SetZoomLevelForViewFromWebContents,
+            info->GetWebContentsGetterForRequest(),
+            info->GetChildID(),
+            info->GetRouteID(),
+            request()->url()));
   }
 
   // If the parent handler downloaded the resource to a file, grant the child