Change for building font cache into separate thread inside utility process so...

Change for building font cache into separate thread inside utility process so that IO thread remains responsive.

BUG=458751, 436195
R=cpu,scottmg

Review URL: https://codereview.chromium.org/1011023002

Cr-Commit-Position: refs/heads/master@{#320983}

chrome/utility/font_cache_handler_win.cc

@@ -4,6 +4,8 @@
 
 #include "chrome/utility/font_cache_handler_win.h"
 
+#include "base/task_runner_util.h"
+#include "base/threading/thread.h"
 #include "chrome/common/chrome_utility_messages.h"
 #include "content/public/common/dwrite_font_platform_win.h"
 #include "content/public/utility/utility_thread.h"
@@ -19,6 +21,30 @@ bool FontCacheHandler::OnMessageReceived(const IPC::Message& message) {
 }
 
 void FontCacheHandler::OnBuildFontCache(const base::FilePath& full_path) {
+  DCHECK(!cache_thread_);
+
+  utility_task_runner_ = base::MessageLoop::current()->message_loop_proxy();
+
+  // Create worker thread for building font cache.
+  cache_thread_.reset(new base::Thread("font_cache_thread"));
+  if (!cache_thread_->Start()) {
+    NOTREACHED();
+    return;
+  }
+  cache_thread_->message_loop()->PostTask(
+      FROM_HERE, base::Bind(&FontCacheHandler::StartBuildingFontCache,
+                            base::Unretained(this),
+                            full_path));
+}
+
+void FontCacheHandler::StartBuildingFontCache(const base::FilePath& full_path) {
   content::BuildFontCache(full_path);
+  utility_task_runner_->PostTask(FROM_HERE,
+                                 base::Bind(&FontCacheHandler::Cleanup,
+                                            base::Unretained(this)));
+}
+
+void FontCacheHandler::Cleanup() {
+  cache_thread_.reset();
   content::UtilityThread::Get()->ReleaseProcessIfNeeded();
 }

chrome/utility/font_cache_handler_win.h

@@ -6,8 +6,15 @@
 #define CHROME_UTILITY_FONT_CACHE_HANDLER_WIN_H_
 
 #include "base/files/file_path.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "chrome/utility/utility_message_handler.h"
 
+namespace base {
+class TaskRunner;
+class Thread;
+}
+
 // Handles requests to build a static direct write font cache. Must be invoked
 // in a non-sandboxed utility process. We build static font cache in utility
 // process as it is time consuming as well as crash prone thing. We already
@@ -24,6 +31,14 @@ class FontCacheHandler : public UtilityMessageHandler {
 
  private:
   void OnBuildFontCache(const base::FilePath& full_path);
+  void StartBuildingFontCache(const base::FilePath& full_path);
+  void Cleanup();
+
+  scoped_refptr<base::TaskRunner> utility_task_runner_;
+
+  // Thread that caching process runs on, while FontCacheHandler handles
+  // messages from the browser process.
+  scoped_ptr<base::Thread> cache_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(FontCacheHandler);
 };