Reduce overhead of SkFontHost_FreeType::onFilterRec.

src/ports/SkFontHost_FreeType.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkAdvancedTypefaceMetrics.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 679 matching lines @@
 }
 
 void SkTypeface_FreeType::onFilterRec(SkScalerContextRec* rec) const {
     //BOGUS: http://code.google.com/p/chromium/issues/detail?id=121119
     //Cap the requested size as larger sizes give bogus values.
     //Remove when http://code.google.com/p/skia/issues/detail?id=554 is fixed.
     if (rec->fTextSize > SkIntToScalar(1 << 14)) {
         rec->fTextSize = SkIntToScalar(1 << 14);
     }
 
-    AutoFTAccess fta(this);
-    if (!gFTLibrary->isLCDSupported() && isLCD(*rec)) {
-        // If the runtime Freetype library doesn't support LCD mode, we disable
-        // it here.
-        rec->fMaskFormat = SkMask::kA8_Format;
+    {
+        // TODO: re-work so that FreeType is set-up and selected by the SkFontMgr.
+        SkAutoMutexAcquire ama(gFTMutex);
+        ref_ft_library();
+        if (!gFTLibrary->isLCDSupported() && isLCD(*rec)) {

[reed1, 2015/01/21 19:29:34]

maybe move the isLCD() check outside of the mutex-grab?

+            // If the runtime Freetype library doesn't support LCD, disable it here.
+            rec->fMaskFormat = SkMask::kA8_Format;
+        }
+        unref_ft_library();
     }
 
     SkPaint::Hinting h = rec->getHinting();
     if (SkPaint::kFull_Hinting == h && !isLCD(*rec)) {
         // collapse full->normal hinting if we're not doing LCD
         h = SkPaint::kNormal_Hinting;
     }
     if ((rec->fFlags & SkScalerContext::kSubpixelPositioning_Flag)) {
         if (SkPaint::kNo_Hinting != h) {
             h = SkPaint::kSlight_Hinting;
@@ skipping 1002 matching lines @@
     if (style) {
         *style = SkFontStyle(weight, width, slant);
     }
     if (isFixedPitch) {
         *isFixedPitch = FT_IS_FIXED_WIDTH(face);
     }
 
     FT_Done_Face(face);
     return true;
 }