Avoid triggering DWriteFontLookupTableBuilder callbacks in shutdown

Speculative fix for test flakiness in issues below.

As per dcheng@'s recommendations in issue 1066456, remove
CallbackWrappers:

1) For DWriteFontProxyImpl::GetUniqueNameLookupTableIfAvailable we can
immediately return by calling the callback explicitly.

2) For DWriteFontProxyImpl::GetUniqueNameLookupTable the callback is
enqueued in DWriteFontLookupTableBuilder in a
base::DeferredSequencedTaskRunner and gets run from there or does not
during shutdown - which is as expected. No need for an extra wrapper.

Bug: 1066456
Change-Id: I21891bd3cf5db7379b9e8d366cb405e7f43e8326
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2164828
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762871}

chrome/browser/about_flags_browsertest.cc

@@ -350,13 +350,7 @@ IN_PROC_BROWSER_TEST_P(AboutFlagsBrowserTest, DISABLED_ExpiredFlagDoesntApply) {
 }
 #endif
 
-// Flaky on Windows 7: https://crbug.com/1066456
-#if defined(OS_WIN)
-#define MAYBE_FormRestore DISABLED_FormRestore
-#else
-#define MAYBE_FormRestore FormRestore
-#endif
-IN_PROC_BROWSER_TEST_P(AboutFlagsBrowserTest, MAYBE_FormRestore) {
+IN_PROC_BROWSER_TEST_P(AboutFlagsBrowserTest, FormRestore) {
   NavigateToFlagsPage();
   content::WebContents* contents =
       browser()->tab_strip_model()->GetActiveWebContents();

chrome/browser/ui/webui/extensions/extension_settings_browsertest.cc

@@ -217,15 +217,8 @@ IN_PROC_BROWSER_TEST_F(ExtensionSettingsUIBrowserTest, ListenerRegistration) {
   }
 }
 
-// Flaky on Windows: crbug.com/
-#if defined(OS_WIN)
-#define MAYBE_ActivityLogInactiveWithoutSwitch \
-  DISABLED_ActivityLogInactiveWithoutSwitch
-#else
-#define MAYBE_ActivityLogInactiveWithoutSwitch ActivityLogInactiveWithoutSwitch
-#endif  // OS_WIN
 IN_PROC_BROWSER_TEST_F(ExtensionSettingsUIBrowserTest,
-                       MAYBE_ActivityLogInactiveWithoutSwitch) {
+                       ActivityLogInactiveWithoutSwitch) {
   // Navigate to chrome://extensions which is a whitelisted URL for the
   // chrome.activityLogPrivate API.
   GURL extensions_url("chrome://extensions");

content/browser/renderer_host/dwrite_font_proxy_impl_win.cc

@@ -393,12 +393,10 @@ void DWriteFontProxyImpl::MapCharacters(
 void DWriteFontProxyImpl::GetUniqueNameLookupTableIfAvailable(
     GetUniqueNameLookupTableIfAvailableCallback callback) {
   DCHECK(base::FeatureList::IsEnabled(features::kFontSrcLocalMatching));
-  base::ReadOnlySharedMemoryRegion invalid_region;
-  callback = mojo::WrapCallbackWithDefaultInvokeIfNotRun(
-      std::move(callback), false, std::move(invalid_region));
-
+  /* Table is not synchronously available, return immediately. */
   if (!DWriteFontLookupTableBuilder::GetInstance()
            ->FontUniqueNameTableReady()) {
+    std::move(callback).Run(false, base::ReadOnlySharedMemoryRegion());
     return;
   }
 
@@ -497,9 +495,6 @@ void DWriteFontProxyImpl::GetUniqueFontLookupMode(
 void DWriteFontProxyImpl::GetUniqueNameLookupTable(
     GetUniqueNameLookupTableCallback callback) {
   DCHECK(base::FeatureList::IsEnabled(features::kFontSrcLocalMatching));
-  callback = mojo::WrapCallbackWithDefaultInvokeIfNotRun(
-      std::move(callback), base::ReadOnlySharedMemoryRegion());
-
   DWriteFontLookupTableBuilder::GetInstance()->QueueShareMemoryRegionWhenReady(
       base::SequencedTaskRunnerHandle::Get(), std::move(callback));
 }