Consistently use LoFi for an entire page

content/browser/loader/resource_dispatcher_host_impl.cc

Index: content/browser/loader/resource_dispatcher_host_impl.cc
diff --git a/content/browser/loader/resource_dispatcher_host_impl.cc b/content/browser/loader/resource_dispatcher_host_impl.cc
index c5c679656570f87722b183927bd5d1313e4cd934..dd3444ec4c3075dd18550f75c16481cc04377b63 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -1322,6 +1322,17 @@ void ResourceDispatcherHostImpl::BeginRequest(
   }
   new_request->SetLoadFlags(load_flags);
 
+  bool is_lofi;

[mmenke, 2015/09/29 16:35:57]

Maybe is_lofi -> use_lofi / using_lofi / is_using_lofi?  modifies a bunch of
files, but think it's clearer.  "This request uses lofi" seems clearer than
"this request is lofi" to me.

[megjablon, 2015/09/29 21:20:07]

Done.

+  if (request_data.lofi_state == LOFI_DEFAULT &&

[mmenke, 2015/09/29 16:35:57]

I think this code makes more sense if LOFI_DEFAULT is renamed to
LOFI_UNSPECIFIED.  "Default" implies a single default value, but we're letting
the delegate set it on a per-request basis, rather than using a default value.

[megjablon, 2015/09/29 21:20:07]

Done.

+      (load_flags & net::LOAD_MAIN_FRAME) != 0 && delegate_) {

[mmenke, 2015/09/29 16:35:57]

I don't see why we shouldn't call into the delegate on non-main frames, when
lofi_state is is LOFI_DEFAULT.

[megjablon, 2015/09/29 21:20:07]

Done.

+    is_lofi = delegate_->ShouldEnableLoFiMode(new_request.get(),
+                                              resource_context);
+  } else if (request_data.lofi_state == LOFI_ON) {
+    is_lofi = true;
+  } else {
+    is_lofi = false;

[mmenke, 2015/09/29 16:35:57]

Question:  Do favicons also inherit the lofi bit from the main page?  That may
be problematic, if they're shared via sync.

[megjablon, 2015/09/29 21:20:07]

The proxy has logic so that icons and button images aren't "LoFi-ed". Testing it
out, I haven't seen a favicon that got the placeholder, but I'll have to ask if
favicons are explicitly filtered out or if they just happen to be detected by
the logic that finds icons.

+  }
+
   // Make extra info and read footer (contains request ID).
   ResourceRequestInfoImpl* extra_info = new ResourceRequestInfoImpl(
       process_type, child_id, route_id,
@@ -1346,7 +1357,8 @@ void ResourceDispatcherHostImpl::BeginRequest(
       request_data.visiblity_state,
       resource_context, filter_->GetWeakPtr(),
       report_raw_headers,
-      !is_sync_load);
+      !is_sync_load,
+      is_lofi);
   // Request takes ownership.
   extra_info->AssociateWithRequest(new_request.get());
 
@@ -1622,7 +1634,8 @@ ResourceRequestInfoImpl* ResourceDispatcherHostImpl::CreateRequestInfo(
       context,
       base::WeakPtr<ResourceMessageFilter>(),  // filter
       false,                                   // report_raw_headers
-      true);                                   // is_async
+      true,                                    // is_async
+      false);                                  // is_lofi
 }
 
 void ResourceDispatcherHostImpl::OnRenderViewHostCreated(int child_id,
@@ -2033,6 +2046,16 @@ void ResourceDispatcherHostImpl::BeginNavigationRequest(
 
   request_id_--;
 
+  bool is_lofi;
+  if (info.common_params.lofi_state == LOFI_DEFAULT && delegate_) {
+    is_lofi = delegate_->ShouldEnableLoFiMode(new_request.get(),
+                                              resource_context);
+  } else if (info.common_params.lofi_state == LOFI_ON) {
+    is_lofi = true;
+  } else {
+    is_lofi = false;
+  }
+
   // Make extra info and read footer (contains request ID).
   //
   // TODO(davidben): Associate the request with the FrameTreeNode and/or tab so
@@ -2068,7 +2091,8 @@ void ResourceDispatcherHostImpl::BeginNavigationRequest(
       resource_context,
       base::WeakPtr<ResourceMessageFilter>(),  // filter
       false,  // request_data.report_raw_headers
-      true);
+      true,
+      is_lofi);
   // Request takes ownership.
   extra_info->AssociateWithRequest(new_request.get());