Convert --enable-md-history to a feature flag.

The Material Design history flag (#enable-md-history) uses the old-style
UI with only an enable/disable button. It should have a drop-down with
"Default", "Enable", "Disable" like all new feature flags.

BUG=586340

Review URL: https://codereview.chromium.org/1766273002

Cr-Commit-Position: refs/heads/master@{#381662}

chrome/browser/about_flags.cc

@@ -1693,7 +1693,7 @@ const FeatureEntry kFeatureEntries[] = {
 #endif  // OS_ANDROID
     {"enable-md-history", IDS_FLAGS_ENABLE_MATERIAL_DESIGN_HISTORY_NAME,
      IDS_FLAGS_ENABLE_MATERIAL_DESIGN_HISTORY_DESCRIPTION, kOsDesktop,
-     SINGLE_VALUE_TYPE(switches::kEnableMaterialDesignHistory)},
+     FEATURE_VALUE_TYPE(features::kMaterialDesignHistoryFeature)},
 #if defined(OS_WIN)
     {"enable-windows-desktop-search-redirection",
      IDS_FLAGS_WINDOWS_DESKTOP_SEARCH_REDIRECTION_NAME,

chrome/browser/browser_about_handler.cc

@@ -15,6 +15,7 @@
 #include "build/build_config.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/browser/ui/browser_dialogs.h"
+#include "chrome/common/chrome_features.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/url_constants.h"
 #include "components/url_formatter/url_fixer.h"
@@ -74,7 +75,7 @@ bool WillHandleBrowserAboutURL(GURL* url,
   } else if (host == chrome::kChromeUIHistoryHost) {
     // Material design history is handled on the top-level chrome://history
     // host.
-    if (::switches::MdHistoryEnabled()) {
+    if (base::FeatureList::IsEnabled(features::kMaterialDesignHistoryFeature)) {
       host = chrome::kChromeUIHistoryHost;
       path = url->path();
     } else {

chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc

@@ -55,6 +55,7 @@
 #include "chrome/browser/ui/webui/translate_internals/translate_internals_ui.h"
 #include "chrome/browser/ui/webui/user_actions/user_actions_ui.h"
 #include "chrome/browser/ui/webui/version_ui.h"
+#include "chrome/common/chrome_features.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
@@ -400,7 +401,7 @@ WebUIFactoryFunction GetWebUIFactoryFunction(WebUI* web_ui,
     return &NewWebUI<extensions::ExtensionsUI>;
   }
   // Material Design history is on its own host, rather than on an Uber page.
-  if (::switches::MdHistoryEnabled() &&
+  if (base::FeatureList::IsEnabled(features::kMaterialDesignHistoryFeature) &&
       url.host() == chrome::kChromeUIHistoryHost) {
     return &NewWebUI<MdHistoryUI>;
   }

chrome/browser/ui/webui/uber/uber_ui.cc

@@ -11,6 +11,7 @@
 #include "chrome/browser/ui/webui/extensions/extensions_ui.h"
 #include "chrome/browser/ui/webui/log_web_ui_url.h"
 #include "chrome/browser/ui/webui/options/options_ui.h"
+#include "chrome/common/chrome_features.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/chrome_manifest_url_handlers.h"
 #include "chrome/common/url_constants.h"
@@ -108,8 +109,11 @@ content::WebUIDataSource* CreateUberFrameHTMLSource(
   bool overrides_history =
       HasExtensionType(browser_context, chrome::kChromeUIHistoryHost);
   source->AddString("overridesHistory", overrides_history ? "yes" : "no");
-  source->AddBoolean("hideHistory",
-                     ::switches::MdHistoryEnabled() && !overrides_history);
+  source->AddBoolean(
+      "hideHistory",
+      base::FeatureList::IsEnabled(features::kMaterialDesignHistoryFeature)
+      && !overrides_history);
+
   source->DisableDenyXFrameOptions();
   source->OverrideContentSecurityPolicyFrameSrc("frame-src chrome:;");
 

chrome/browser/ui/webui/uber/uber_ui_browsertest.cc

@@ -12,10 +12,12 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/common/chrome_features.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "chrome/test/base/web_ui_browser_test.h"
+#include "content/public/common/content_switches.h"
 #include "content/public/test/browser_test_utils.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension.h"
@@ -92,8 +94,12 @@ IN_PROC_BROWSER_TEST_F(UberUIBrowserTest, EnableMdExtensionsHidesExtensions) {
 }
 
 IN_PROC_BROWSER_TEST_F(UberUIBrowserTest, EnableMdHistoryHidesHistory) {
-  base::CommandLine::ForCurrentProcess()->AppendSwitch(
-    ::switches::kEnableMaterialDesignHistory);
+  scoped_ptr<base::FeatureList> feature_list(new base::FeatureList);
+  feature_list->InitializeFromCommandLine(
+      features::kMaterialDesignHistoryFeature.name, "");
+  base::FeatureList::ClearInstanceForTesting();
+  base::FeatureList::SetInstance(std::move(feature_list));
+
   ui_test_utils::NavigateToURL(browser(), GURL(chrome::kChromeUIUberFrameURL));
   SelectTab();
   EXPECT_TRUE(GetJsBool("$('history').hidden"));

chrome/common/chrome_features.cc

@@ -22,6 +22,11 @@ const base::Feature kLinuxObsoleteSystemIsEndOfTheLine{
     "LinuxObsoleteSystemIsEndOfTheLine", base::FEATURE_DISABLED_BY_DEFAULT};
 #endif
 
+// Enables or disables the Material Design version of chrome://history.
+const base::Feature kMaterialDesignHistoryFeature {
+  "MaterialDesignHistory", base::FEATURE_DISABLED_BY_DEFAULT
+};
+
 #if defined(OS_CHROMEOS)
 // Runtime flag that indicates whether this leak detector should be enabled in
 // the current instance of Chrome.

chrome/common/chrome_features.h

@@ -23,6 +23,7 @@ extern const base::Feature kAutomaticTabDiscarding;
 extern const base::Feature kLinuxObsoleteSystemIsEndOfTheLine;
 #endif
 
+extern const base::Feature kMaterialDesignHistoryFeature;
 
 #if defined(OS_CHROMEOS)
 extern const base::Feature kRuntimeMemoryLeakDetector;

chrome/common/chrome_switches.cc

@@ -426,9 +426,6 @@ const char kEnableFastUnload[] = "enable-fast-unload";
 // Enables the Material Design version of chrome://extensions.
 const char kEnableMaterialDesignExtensions[] = "enable-md-extensions";
 
-// Enables the Material Design version of chrome://history.
-const char kEnableMaterialDesignHistory[] = "enable-md-history";
-
 // Enables the Material Design policy page at chrome://md-policy.
 const char kEnableMaterialDesignPolicyPage[]  = "enable-md-policy-page";
 
@@ -1349,11 +1346,6 @@ bool MdExtensionsEnabled() {
       ::switches::kEnableMaterialDesignExtensions);
 }
 
-bool MdHistoryEnabled() {
-  return base::CommandLine::ForCurrentProcess()->HasSwitch(
-      ::switches::kEnableMaterialDesignHistory);
-}
-
 bool MdPolicyPageEnabled() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       ::switches::kEnableMaterialDesignPolicyPage);

chrome/common/chrome_switches.h

@@ -122,7 +122,6 @@ extern const char kEnableExtensionActivityLogging[];
 extern const char kEnableExtensionActivityLogTesting[];
 extern const char kEnableFastUnload[];
 extern const char kEnableMaterialDesignExtensions[];
-extern const char kEnableMaterialDesignHistory[];
 extern const char kEnableMaterialDesignPolicyPage[];
 extern const char kEnableNaCl[];
 extern const char kEnableNativeNotifications[];
@@ -402,7 +401,6 @@ extern const char kDisableInputImeAPI[];
 
 bool AboutInSettingsEnabled();
 bool MdExtensionsEnabled();
-bool MdHistoryEnabled();
 bool MdPolicyPageEnabled();
 bool PdfMaterialUIEnabled();
 bool SettingsWindowEnabled();

chrome/test/data/webui/md_history/md_history_browsertest.js

@@ -20,7 +20,8 @@ MaterialHistoryBrowserTest.prototype = {
 
   browsePreload: 'chrome://history',
 
-  commandLineSwitches: [{switchName: 'enable-md-history'}],
+  commandLineSwitches: [{switchName: 'enable-features',
+                         switchValue: 'MaterialDesignHistory'}],
 
   /** @override */
   runAccessibilityChecks: false,