Use ChildThreadImpl::thread_safe_sender in font proxy if available

content/child/dwrite_font_proxy/dwrite_font_proxy_win.cc

Index: content/child/dwrite_font_proxy/dwrite_font_proxy_win.cc
diff --git a/content/child/dwrite_font_proxy/dwrite_font_proxy_win.cc b/content/child/dwrite_font_proxy/dwrite_font_proxy_win.cc
index 932393da9ddff68d39d3864e51ec66200a0a1c21..5b9f6eb9c84a4835335f83ce6afe7e2c41356d10 100644
--- a/content/child/dwrite_font_proxy/dwrite_font_proxy_win.cc
+++ b/content/child/dwrite_font_proxy/dwrite_font_proxy_win.cc
@@ -97,7 +97,7 @@ HRESULT DWriteFontCollectionProxy::FindFamilyName(const WCHAR* family_name,
     return S_OK;
   }
 
-  if (!GetSender()->Send(
+  if (!sender_.Run()->Send(
           new DWriteFontProxyMsg_FindFamily(name, &family_index))) {
     LogFontProxyError(FIND_FAMILY_SEND_FAILED);
     return E_FAIL;
@@ -142,7 +142,7 @@ UINT32 DWriteFontCollectionProxy::GetFontFamilyCount() {
   TRACE_EVENT0("dwrite", "FontProxy::GetFontFamilyCount");
 
   uint32_t family_count = 0;
-  if (!GetSender()->Send(
+  if (!sender_.Run()->Send(
           new DWriteFontProxyMsg_GetFamilyCount(&family_count))) {
     LogFontProxyError(GET_FAMILY_COUNT_SEND_FAILED);
     return 0;
@@ -195,7 +195,7 @@ HRESULT DWriteFontCollectionProxy::CreateEnumeratorFromKey(
 
   std::vector<base::string16> file_names;
   std::vector<IPC::PlatformFileForTransit> file_handles;
-  if (!GetSender()->Send(new DWriteFontProxyMsg_GetFontFiles(
+  if (!sender_.Run()->Send(new DWriteFontProxyMsg_GetFontFiles(
           *family_index, &file_names, &file_handles))) {
     LogFontProxyError(GET_FONT_FILES_SEND_FAILED);
     return E_FAIL;
@@ -259,11 +259,11 @@ HRESULT DWriteFontCollectionProxy::CreateStreamFromKey(
 
 HRESULT DWriteFontCollectionProxy::RuntimeClassInitialize(
     IDWriteFactory* factory,
-    IPC::Sender* sender_override) {
+    const base::Callback<IPC::Sender*(void)>& sender) {
   DCHECK(factory);
 
   factory_ = factory;
-  sender_override_ = sender_override;
+  sender_ = sender;
 
   HRESULT hr = factory->RegisterFontCollectionLoader(this);
   DCHECK(SUCCEEDED(hr));
@@ -314,7 +314,7 @@ bool DWriteFontCollectionProxy::LoadFamilyNames(
   TRACE_EVENT0("dwrite", "FontProxy::LoadFamilyNames");
 
   std::vector<std::pair<base::string16, base::string16>> strings;
-  if (!GetSender()->Send(
+  if (!sender_.Run()->Send(
           new DWriteFontProxyMsg_GetFamilyNames(family_index, &strings))) {
     return false;
   }
@@ -347,10 +347,6 @@ bool DWriteFontCollectionProxy::CreateFamily(UINT32 family_index) {
   return true;
 }
 
-IPC::Sender* DWriteFontCollectionProxy::GetSender() {
-  return sender_override_ ? sender_override_ : ChildThread::Get();

[jam, 2016/07/28 16:34:31]

you can fix this by changing

ChildThread::Get()
to
ChildThreadImpl::current()->thread_safe_sender()

[Ilya Kulshin, 2016/07/28 19:01:13]

thread_safe_sender still needs to be called from the main thread, since it
obtains the sender from tls. At the point where I know this code is running from
the main thread (initialization) the IPC system is not yet fully functional, so
I cannot get the sender at that time. By the time the code gets here, it can no
longer be relied to be on the main thread, so thread_safe_sender will not work.

-}
-
 DWriteFontFamilyProxy::DWriteFontFamilyProxy() = default;
 
 DWriteFontFamilyProxy::~DWriteFontFamilyProxy() = default;