Switch to direct write font proxy and remove the font cache.

chrome/browser/chrome_browser_main_win.cc

Index: chrome/browser/chrome_browser_main_win.cc
diff --git a/chrome/browser/chrome_browser_main_win.cc b/chrome/browser/chrome_browser_main_win.cc
index 0e2e53abc5ebacb9f4a36634b33da13ef294d592..bfad64d60b2cb77c584e365075ccbf7685588b13 100644
--- a/chrome/browser/chrome_browser_main_win.cc
+++ b/chrome/browser/chrome_browser_main_win.cc
@@ -57,7 +57,6 @@
 #include "content/public/browser/utility_process_host.h"
 #include "content/public/browser/utility_process_host_client.h"
 #include "content/public/common/content_switches.h"
-#include "content/public/common/dwrite_font_platform_win.h"
 #include "content/public/common/main_function_params.h"
 #include "ui/base/cursor/cursor_loader_win.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -83,6 +82,8 @@ typedef HRESULT (STDAPICALLTYPE* RegisterApplicationRestartProc)(
     const wchar_t* command_line,
     DWORD flags);
 
+const char kFontCacheSharedSectionName[] = "ChromeDWriteFontCache";
+
 void InitializeWindowProcExceptions() {
   // Get the breakpad pointer from chrome.exe
   base::win::WinProcExceptionFilter exception_filter =
@@ -111,16 +112,6 @@ class TranslationDelegate : public installer::TranslationDelegate {
   base::string16 GetLocalizedString(int installer_string_id) override;
 };
 
-void ExecuteFontCacheBuildTask(const base::FilePath& path) {
-  base::WeakPtr<content::UtilityProcessHost> utility_process_host(
-      content::UtilityProcessHost::Create(NULL, NULL)->AsWeakPtr());
-  utility_process_host->SetName(l10n_util::GetStringUTF16(
-      IDS_UTILITY_PROCESS_FONT_CACHE_BUILDER_NAME));
-  utility_process_host->DisableSandbox();
-  utility_process_host->Send(
-      new ChromeUtilityHostMsg_BuildDirectWriteFontCache(path));
-}
-
 #if defined(KASKO)
 void ObserveFailedCrashReportDirectory(const base::FilePath& path, bool error) {
   DCHECK(!error);
@@ -215,6 +206,11 @@ void DetectFaultTolerantHeap() {
   UMA_HISTOGRAM_ENUMERATION("FaultTolerantHeap", detected, FTH_FLAGS_COUNT);
 }
 
+void DeleteDirectWriteFontCache(base::FilePath path) {
+  // Attempt to delte the font cache and ignore any errors.

[fdoray, 2015/12/23 13:45:02]

*delete

[Ilya Kulshin, 2015/12/28 22:47:05]

Done.

+  ::DeleteFile(path.AsUTF16Unsafe().c_str());

[fdoray, 2015/12/23 13:45:02]

base::DeleteFile? base/files/file_util.h

[Ilya Kulshin, 2015/12/28 22:47:05]

Done.

+}
+
 }  // namespace
 
 void ShowCloseBrowserFirstMessageBox() {
@@ -342,33 +338,17 @@ void ChromeBrowserMainPartsWin::ShowMissingLocaleMessageBox() {
 void ChromeBrowserMainPartsWin::PostProfileInit() {
   ChromeBrowserMainParts::PostProfileInit();
 
-  // DirectWrite support is mainly available Windows 7 and up.
   if (gfx::win::ShouldUseDirectWrite()) {
+    // Clean up the direct write font cache since we no longer use that
+    // codepath.
+    // TODO(kulshin): remove this code after several releases.

[fdoray, 2015/12/23 13:45:02]

I would have been curious to see the impact of this change on startup and page
load time. A field trial could have been used for that -> x% of users use the
old font cache and x% use the new technique. I'm happy to help if you decide to
do a field trial.

     base::FilePath path(
-      profile()->GetPath().AppendASCII(content::kFontCacheSharedSectionName));
-    // This function will create a read only section if cache file exists
-    // otherwise it will spawn utility process to build cache file, which will
-    // be used during next browser start/postprofileinit.
-    if (!content::LoadFontCache(path)) {
-      // We delay building of font cache until first startup page loads.
-      // During first renderer start there are lot of things happening
-      // simultaneously some of them are:
-      // - Renderer is going through all font files on the system to create
-      //   a font collection.
-      // - Renderer loading up startup URL, accessing HTML/JS File cache,
-      //   net activity etc.
-      // - Extension initialization.
-      // We delay building of cache mainly to avoid parallel font file
-      // loading along with Renderer. Some systems have significant number of
-      // font files which takes long time to process.
-      // Related information is at http://crbug.com/436195.
-      const int kBuildFontCacheDelaySec = 30;
-      content::BrowserThread::PostDelayedTask(
-          content::BrowserThread::IO,
-          FROM_HERE,
-          base::Bind(ExecuteFontCacheBuildTask, path),
-          base::TimeDelta::FromSeconds(kBuildFontCacheDelaySec));
-    }
+        profile()->GetPath().AppendASCII(kFontCacheSharedSectionName));
+    const int kBuildFontCacheDelaySec = 30;
+    content::BrowserThread::PostDelayedTask(
+        content::BrowserThread::IO, FROM_HERE,

[fdoray, 2015/12/23 13:45:02]

content::BrowserThread::FILE is the right thread for this. IO is for
"non-blocking IO, i.e. IPC and network". content/public/browser/browser_thread.h

[Ilya Kulshin, 2015/12/28 22:47:05]

Done.

+        base::Bind(DeleteDirectWriteFontCache, path),
+        base::TimeDelta::FromSeconds(kBuildFontCacheDelaySec));
   }
 }