Revert "Share DWriteFontProxyImpl TaskRunner to DWriteFontLookupTableBuilder"

This reverts commit 0e244ee9.

Reason for revert: Causes flakiness in FontUniqueNameBrowserTest.ContentLocalFontsMatching

Original change's description:
> Share DWriteFontProxyImpl TaskRunner to DWriteFontLookupTableBuilder
> 
> Preparation for a follow-up CL that actually making queries for the font
> lookup table asynchronous. In that CL, DWriteFontLookupTableBuilder
> needs the task runner to run the Mojo message callback on the same task
> runner on which DWriteFontProxyImpl received it.
> 
> Move scheduling the lookup table construction to
> common_browser_interfaces.cc which is still around the same time in
> startup as before, but makes it much easier to share the same task
> runner.
> 
> Bug: 960263, 889864
> Tbr: avi
> Change-Id: I8be6d4a4d29014967d38f20ccf8a94948a7b8a1e
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1626865
> Commit-Queue: Dominik Röttsches <drott@chromium.org>
> Reviewed-by: Dominik Röttsches <drott@chromium.org>
> Reviewed-by: Ken Rockot <rockot@google.com>
> Reviewed-by: François Doray <fdoray@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#663021}

TBR=avi@chromium.org,rockot@google.com,fdoray@chromium.org,drott@chromium.org

Change-Id: Ie88de224e40862a3fa62618c553501e51aa29599
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 960263, 889864
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1628712Reviewed-by: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663039}

content/browser/browser_main_loop.cc

@@ -1420,6 +1420,11 @@ int BrowserMainLoop::BrowserThreadsStarted() {
           switches::kDisableGpuProcessForDX12VulkanInfoCollection)) {
     GpuDataManagerImpl::GetInstance()->RequestGpuSupportedRuntimeVersion();
   }
+
+  if (base::FeatureList::IsEnabled(features::kFontSrcLocalMatching)) {
+    content::DWriteFontLookupTableBuilder::GetInstance()
+        ->SchedulePrepareFontUniqueNameTableIfNeeded();
+  }
 #endif
 
   if (MediaKeysListenerManager::IsMediaKeysListenerManagerEnabled()) {

content/browser/renderer_host/dwrite_font_lookup_table_builder_win.h

@@ -17,10 +17,8 @@
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/read_only_shared_memory_region.h"
-#include "base/memory/scoped_refptr.h"
 #include "base/memory/singleton.h"
 #include "base/optional.h"
-#include "base/sequenced_task_runner.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/time/time.h"
 #include "content/common/content_export.h"
@@ -46,13 +44,6 @@ class CONTENT_EXPORT DWriteFontLookupTableBuilder {
  public:
   static DWriteFontLookupTableBuilder* GetInstance();
 
-  // Configure the task runner that will be used for posting tasks to when
-  // executing Mojo result callbacks that were passed from DWriteFontProxyImpl.
-  void SetCallbackTaskRunner(
-      scoped_refptr<base::SequencedTaskRunner> callback_task_runner) {
-    callback_task_runner_ = callback_task_runner;
-  }
-
   // Retrieve the prepared memory region if it is available.
   // EnsureFontUniqueNameTable() must be checked before.
   base::ReadOnlySharedMemoryRegion DuplicateMemoryRegion();
@@ -200,7 +191,6 @@ class CONTENT_EXPORT DWriteFontLookupTableBuilder {
   bool caching_enabled_ = true;
   base::Optional<base::WaitableEvent> hang_event_for_testing_;
   base::CancelableOnceCallback<void()> timeout_callback_;
-  scoped_refptr<base::SequencedTaskRunner> callback_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(DWriteFontLookupTableBuilder);
 };

content/browser/service_manager/common_browser_interfaces.cc

@@ -11,7 +11,6 @@
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
-#include "base/feature_list.h"
 #include "base/memory/ref_counted.h"
 #include "base/task/post_task.h"
 #include "base/task_runner.h"
@@ -24,7 +23,6 @@
 #include "content/public/browser/browser_task_traits.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/connection_filter.h"
-#include "content/public/common/content_features.h"
 #include "content/public/common/service_manager_connection.h"
 #include "content/public/common/service_names.mojom.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
@@ -47,19 +45,10 @@ class ConnectionFilterImpl : public ConnectionFilter {
   ConnectionFilterImpl() {
 #if defined(OS_WIN)
     registry_.AddInterface(base::BindRepeating(&FontCacheDispatcher::Create));
-
-    auto dwrite_font_proxy_task_runner =
+    registry_.AddInterface(
+        base::BindRepeating(&DWriteFontProxyImpl::Create),
         base::CreateSequencedTaskRunnerWithTraits(
-            {base::TaskPriority::USER_BLOCKING, base::MayBlock()});
-    registry_.AddInterface(base::BindRepeating(&DWriteFontProxyImpl::Create),
-                           dwrite_font_proxy_task_runner);
-
-    if (base::FeatureList::IsEnabled(features::kFontSrcLocalMatching)) {
-      content::DWriteFontLookupTableBuilder::GetInstance()
-          ->SetCallbackTaskRunner(dwrite_font_proxy_task_runner);
-      content::DWriteFontLookupTableBuilder::GetInstance()
-          ->SchedulePrepareFontUniqueNameTableIfNeeded();
-    }
+            {base::TaskPriority::USER_BLOCKING, base::MayBlock()}));
 #elif defined(OS_MACOSX)
     registry_.AddInterface(
         base::BindRepeating(&SandboxSupportMacImpl::BindRequest,