Introduce FontCache content scaling

content/public/common/content_features.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "build/build_config.h"
 #include "content/public/common/content_features.h"
 
 namespace features {
 
 // All features in alphabetical order.
@@ skipping 17 matching lines @@
 // permanently. See https://crbug.com/7648
 const base::Feature kDownloadResumption{"DownloadResumption",
                                         base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Speculatively pre-evaluate Javascript which will likely use document.write to
 // load an external script. The feature extracts the written markup and sends it
 // to the preload scanner.
 const base::Feature kDocumentWriteEvaluator{"DocumentWriteEvaluator",
                                             base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Enables a blink::FontCache optimization that reuses a font to serve different
+// size of font.

[kinuko, 2016/05/19 14:36:02]

nit: a font -> a cached font ?
nit: different size of font -> different sizes of the font

+const base::Feature kFontCacheScaling{"FontCacheScaling",
+                                      base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Can main thread be pipelined with activation. Always disabled for devices
 // with fewer than 4 cores irrespective of this flag. Can also be overridden by
 // --enable(disable)-main-frame-before-activation command line flag.
 const base::Feature kMainFrameBeforeActivation{
     "MainFrameBeforeActivation", base::FEATURE_DISABLED_BY_DEFAULT};
 
 // FeatureList definition for trials to enable the download button on
 // MediaDocument.
 const base::Feature kMediaDocumentDownloadButton{
     "MediaDocumentDownloadButton",
@@ skipping 68 matching lines @@
 // we will not use replica editor and do a round trip to renderer to synchronize
 // with Blink data.
 const base::Feature kImeThread{"ImeThread", base::FEATURE_DISABLED_BY_DEFAULT};
 
 // FeatureList definition for the Seccomp field trial.
 const base::Feature kSeccompSandboxAndroid{"SeccompSandboxAndroid",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 #endif
 
 }  // namespace features