Make ThemeService::UsingDefaultTheme based on the theme_supplier instead of prefs

This CL is a data dependency refactor that makes
ThemeService::UsingDefaultTheme() based on the current
CustomThemeSupplier rather than prefs. This is in preparation to make
ThemeService::GetColor() based on any CustomThemeSupplier instead of
just the currently installed one. See follow up CL:
https://chromium-review.googlesource.com/c/chromium/src/+/1994026/15

Bug: 1020050
Change-Id: If3bd87e16f6ccf034f4c4909c7f7ca940ee2f838
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2007800Reviewed-by: Evan Stade <estade@chromium.org>
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734275}

chrome/browser/themes/browser_theme_pack.cc

@@ -701,6 +701,7 @@ void BrowserThemePack::BuildFromExtension(
   DCHECK(!pack->is_valid());
 
   pack->InitEmptyPack();
+  pack->set_extension_id(extension->id());
   pack->SetHeaderId(extension);
   pack->SetTintsFromJSON(extensions::ThemeInfo::GetTints(extension));
   pack->SetColorsFromJSON(extensions::ThemeInfo::GetColors(extension));
@@ -733,6 +734,7 @@ scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromDataPack(
   // For now data pack can only have extension type.
   scoped_refptr<BrowserThemePack> pack(
       new BrowserThemePack(ThemeType::EXTENSION));
+  pack->set_extension_id(expected_id);
   // Scale factor parameter is moot as data pack has image resources for all
   // supported scale factors.
   pack->data_pack_.reset(

chrome/browser/themes/custom_theme_supplier.h

@@ -43,6 +43,11 @@ class CustomThemeSupplier
     return theme_type_;
   }
 
+  const std::string& extension_id() const {
+    DCHECK_EQ(theme_type_, EXTENSION);
+    return extension_id_;
+  }
+
   // Called when the theme starts being used.
   virtual void StartUsingTheme();
 
@@ -72,11 +77,17 @@ class CustomThemeSupplier
  protected:
   virtual ~CustomThemeSupplier();
 
+  void set_extension_id(base::StringPiece id) {
+    DCHECK_EQ(theme_type_, EXTENSION);
+    id.CopyToString(&extension_id_);
+  }
+
  private:
   friend class base::RefCountedDeleteOnSequence<CustomThemeSupplier>;
   friend class base::DeleteHelper<CustomThemeSupplier>;
 
   ThemeType theme_type_;
+  std::string extension_id_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomThemeSupplier);
 };

chrome/browser/themes/theme_service.cc

@@ -75,6 +75,17 @@ namespace {
 // unpacked on the filesystem.)
 const char kDefaultThemeGalleryID[] = "hkacjpbfdknhflllbcmjibkdeoafencn";
 
+bool IsDefaultTheme(const CustomThemeSupplier* theme_supplier) {
+  if (!theme_supplier)
+    return true;
+  if (theme_supplier->get_theme_type() !=
+      CustomThemeSupplier::ThemeType::EXTENSION) {
+    return false;
+  }
+  const std::string& id = theme_supplier->extension_id();
+  return id == ThemeService::kDefaultThemeID || id == kDefaultThemeGalleryID;
+}
+
 // Wait this many seconds after startup to garbage collect unused themes.
 // Removing unused themes is done after a delay because there is no
 // reason to do it at startup.
@@ -444,12 +455,16 @@ bool ThemeService::IsSystemThemeDistinctFromDefaultTheme() const {
 }
 
 bool ThemeService::UsingDefaultTheme() const {
-  std::string id = GetThemeID();
-  return id == kDefaultThemeID || id == kDefaultThemeGalleryID;
+  return IsDefaultTheme(get_theme_supplier());
 }
 
 bool ThemeService::UsingSystemTheme() const {
-  return UsingDefaultTheme();
+  return IsSystemTheme(get_theme_supplier());
+}
+
+bool ThemeService::IsSystemTheme(
+    const CustomThemeSupplier* theme_supplier) const {
+  return IsDefaultTheme(theme_supplier);
 }
 
 bool ThemeService::UsingExtensionTheme() const {

chrome/browser/themes/theme_service.h

@@ -108,14 +108,18 @@ class ThemeService : public content::NotificationObserver,
   // this platform.
   virtual bool IsSystemThemeDistinctFromDefaultTheme() const;
 
-  // Whether we're using the chrome default theme. Virtual so linux can check
-  // if we're using the GTK theme.
+  // Whether we're using the chrome default theme.
+  // Virtual for testing.
   virtual bool UsingDefaultTheme() const;
 
-  // Whether we are using the system theme. On GTK, the system theme is the GTK
-  // theme, not the "Classic" theme.
+  // Whether we are using the system theme.
+  // Virtual for testing.
   virtual bool UsingSystemTheme() const;
 
+  // Whether |theme_supplier| is the system theme. On GTK, the system theme is
+  // the GTK theme, not the "Classic" theme
+  virtual bool IsSystemTheme(const CustomThemeSupplier* theme_supplier) const;
+
   // Whether we are using theme installed through extensions.
   // |UsingExtensionTheme| and |UsingDefaultTheme| are not mutually exclusive as
   // default theme can be installed through extensions.

chrome/browser/themes/theme_service_aura_linux.cc

@@ -95,12 +95,8 @@ bool ThemeServiceAuraLinux::IsSystemThemeDistinctFromDefaultTheme() const {
   return true;
 }
 
-bool ThemeServiceAuraLinux::UsingDefaultTheme() const {
-  return ThemeService::UsingDefaultTheme() && !UsingSystemTheme();
-}
-
-bool ThemeServiceAuraLinux::UsingSystemTheme() const {
-  const CustomThemeSupplier* theme_supplier = get_theme_supplier();
+bool ThemeServiceAuraLinux::IsSystemTheme(
+    const CustomThemeSupplier* theme_supplier) const {
   return theme_supplier &&
          theme_supplier->get_theme_type() == CustomThemeSupplier::NATIVE_X11;
 }

chrome/browser/themes/theme_service_aura_linux.h

@@ -21,8 +21,7 @@ class ThemeServiceAuraLinux : public ThemeService {
   bool ShouldInitWithSystemTheme() const override;
   void UseSystemTheme() override;
   bool IsSystemThemeDistinctFromDefaultTheme() const override;
-  bool UsingDefaultTheme() const override;
-  bool UsingSystemTheme() const override;
+  bool IsSystemTheme(const CustomThemeSupplier* theme_supplier) const override;
   void FixInconsistentPreferencesIfNeeded() override;
 
   static bool ShouldUseSystemThemeForProfile(const Profile* profile);