Add custom default theme support and create a managed user default theme.

chrome/browser/themes/custom_theme_supplier.h

+// Copyright 2013 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.
+
+#ifndef CHROME_BROWSER_THEMES_CUSTOM_THEME_SUPPLIER_H_
+#define CHROME_BROWSER_THEMES_CUSTOM_THEME_SUPPLIER_H_
+
+#include "base/memory/ref_counted.h"
+#include "content/public/browser/browser_thread.h"
+#include "third_party/skia/include/core/SkColor.h"
+#include "ui/base/layout.h"
+
+namespace base {
+class RefCountedMemory;
+}
+
+namespace color_utils {
+struct HSL;
+}
+
+namespace gfx {
+class Image;
+}
+
+class CustomThemeSupplier : public base::RefCountedThreadSafe<

[Elliot Glaysher, 2013/07/23 19:57:31]

Again, class documentation. Imagine I'm coming into this not knowing anything
about themes and I see this piece of abstraction.

[Adrian Kuegel, 2013/07/24 12:31:35]

Done.

+    CustomThemeSupplier, content::BrowserThread::DeleteOnFileThread> {
+ public:
+  enum ThemeType {
+    EXTENSION,
+    NATIVE_X11,
+    MANAGED_USER_THEME,
+  };
+
+  explicit CustomThemeSupplier(ThemeType type);
+
+  ThemeType GetThemeType() const {

[Elliot Glaysher, 2013/07/23 19:57:31]

inlined methods should be unix_hacker_cased().

[Adrian Kuegel, 2013/07/24 12:31:35]

Done.

+    return theme_type_;
+  }
+
+  // Called when the theme starts being used.
+  virtual void StartUsingTheme();
+
+  // Called when the theme is not used anymore.
+  virtual void StopUsingTheme();
+
+  // If the theme specifies data for the corresponding |id|, returns true and
+  // writes the corresponding value to the output parameter. These methods
+  // should not return the default data. These methods should only be called
+  // from the UI thread.
+  virtual bool GetTint(int id, color_utils::HSL* hsl) const;
+  virtual bool GetColor(int id, SkColor* color) const;
+  virtual bool GetDisplayProperty(int id, int* result) const;
+
+  // Returns the theme image for |id|. Returns an empty image if no image is
+  // found for |id|.
+  virtual gfx::Image GetImageNamed(int id);
+
+  // Returns the raw PNG encoded data for IDR_THEME_NTP_*. This method only
+  // works for the NTP attribution and background resources.
+  virtual base::RefCountedMemory* GetRawData(
+      int id, ui::ScaleFactor scale_factor) const;
+
+  // Whether this theme provides an image for |id|.
+  virtual bool HasCustomImage(int id) const;
+
+ protected:
+  virtual ~CustomThemeSupplier();
+
+ private:
+  friend struct content::BrowserThread::DeleteOnThread<
+      content::BrowserThread::FILE>;
+  friend class base::DeleteHelper<CustomThemeSupplier>;
+
+  ThemeType theme_type_;
+
+  DISALLOW_COPY_AND_ASSIGN(CustomThemeSupplier);
+};
+
+#endif  // CHROME_BROWSER_THEMES_CUSTOM_THEME_SUPPLIER_H_