[Favicon] Add new fallback icon rendering flow.

components/favicon_base/favicon_types.cc

 // Copyright 2014 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 "components/favicon_base/favicon_types.h"
 
 namespace favicon_base {
 
-// FaviconImageResult ---------------------------------------------------------
+// ---------------------------------------------------------
+// FaviconImageResult
 
 FaviconImageResult::FaviconImageResult() {}
 
 FaviconImageResult::~FaviconImageResult() {}
 
+// --------------------------------------------------------
 // FaviconRawBitmapResult
-// --------------------------------------------------------
 
 FaviconRawBitmapResult::FaviconRawBitmapResult()
     : expired(false), icon_type(INVALID_ICON) {
 }
 
 FaviconRawBitmapResult::~FaviconRawBitmapResult() {
 }
 
-}  // namespace chrome
+// --------------------------------------------------------
+// FallbackIconStyle
+
+FallbackIconStyle::FallbackIconStyle()
+    : background_color(SK_ColorTRANSPARENT),
+      text_color(SK_ColorTRANSPARENT),
+      font_size_ratio(0.0),
+      roundness(0.0) {

[pkotwicz, 2015/01/21 19:44:16]

Can the constructor initialize FallbackIconStyle with the defaults?

[huangs, 2015/01/22 01:13:28]

The default text color depends on the background color: it's black for bright
background and white for dark background.  If we initialize other fields then
we'll have scattered default values.  Therefore I'm letting
FallbackIconStyleBuilder handle all the defaults, and just initialize them to
useless values in the constructor.

+}
+
+FallbackIconStyle::~FallbackIconStyle() {
+}
+
+}  // namespace favicon_base