Add a flag to hide scroll bar in notification list

ARC++ notifications are shown above scroll bar, so we temporarily make scroll bar invisible as a workaround. When the limitation is removed from ARC++, the flag will be removed and the scroll bar will be restored. TEST=manual BUG=858940 Change-Id: I6931c6406c9feb2bb4159d737205187bdc88b86b Reviewed-on: https://chromium-review.googlesource.com/1140014 Reviewed-by: Mitsuru Oshima <oshima@chromium.org> Reviewed-by: Yoshiki Iguchi <yoshiki@chromium.org> Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org> Cr-Commit-Position: refs/heads/master@{#576755}
Denger-Network · Jul 20, 2018 · c3eb87f · c3eb87f
1 parent 62da7b8
commit c3eb87f
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Showing 7 changed files with 31 additions and 1 deletion.
diff --git a/ash/message_center/message_center_scroll_bar.cc b/ash/message_center/message_center_scroll_bar.cc
@@ -4,6 +4,7 @@
 
 #include "ash/message_center/message_center_scroll_bar.h"
 
+#include "ash/public/cpp/ash_features.h"
 #include "base/metrics/histogram_macros.h"
 
 namespace {
@@ -26,7 +27,10 @@ void CollectScrollActionReason(ScrollActionReason reason) {
 namespace ash {
 
 MessageCenterScrollBar::MessageCenterScrollBar()
-    : views::OverlayScrollBar(false) {}
+    : views::OverlayScrollBar(false) {
+  GetThumb()->layer()->SetVisible(!features::IsSystemTrayUnifiedEnabled() ||
+                                  features::IsNotificationScrollBarEnabled());
+}
 
 bool MessageCenterScrollBar::OnKeyPressed(const ui::KeyEvent& event) {
   if (!stats_recorded_ &&

diff --git a/ash/public/cpp/ash_features.cc b/ash/public/cpp/ash_features.cc
@@ -36,6 +36,9 @@ const base::Feature kNewWallpaperPicker{"NewWallpaperPicker",
 
 const base::Feature kNightLight{"NightLight", base::FEATURE_ENABLED_BY_DEFAULT};
 
+const base::Feature kNotificationScrollBar{"NotificationScrollBar",
+                                           base::FEATURE_DISABLED_BY_DEFAULT};
+
 const base::Feature kOverviewSwipeToClose{"OverviewSwipeToClose",
                                           base::FEATURE_DISABLED_BY_DEFAULT};
 
@@ -76,6 +79,10 @@ bool IsNightLightEnabled() {
   return base::FeatureList::IsEnabled(kNightLight);
 }
 
+bool IsNotificationScrollBarEnabled() {
+  return base::FeatureList::IsEnabled(kNotificationScrollBar);
+}
+
 bool IsSystemTrayUnifiedEnabled() {
   return base::FeatureList::IsEnabled(kSystemTrayUnified);
 }

diff --git a/ash/public/cpp/ash_features.h b/ash/public/cpp/ash_features.h
@@ -52,6 +52,9 @@ ASH_PUBLIC_EXPORT extern const base::Feature kNewWallpaperPicker;
 // Enables the Night Light feature.
 ASH_PUBLIC_EXPORT extern const base::Feature kNightLight;
 
+// Enables notification scroll bar in UnifiedSystemTray.
+ASH_PUBLIC_EXPORT extern const base::Feature kNotificationScrollBar;
+
 // Enables swipe to close in overview mode.
 // TODO(sammiequon): Remove this after the feature is fully launched.
 // https://crbug.com/828646.
@@ -81,6 +84,8 @@ ASH_PUBLIC_EXPORT bool IsNewWallpaperPickerEnabled();
 
 ASH_PUBLIC_EXPORT bool IsNightLightEnabled();
 
+ASH_PUBLIC_EXPORT bool IsNotificationScrollBarEnabled();
+
 ASH_PUBLIC_EXPORT bool IsSystemTrayUnifiedEnabled();
 
 ASH_PUBLIC_EXPORT bool IsTrilinearFilteringEnabled();

diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
@@ -1528,6 +1528,10 @@ const FeatureEntry kFeatureEntries[] = {
     {"ash-enable-night-light", flag_descriptions::kEnableNightLightName,
      flag_descriptions::kEnableNightLightDescription, kOsCrOS,
      FEATURE_VALUE_TYPE(ash::features::kNightLight)},
+    {"ash-enable-notification-scroll-bar",
+     flag_descriptions::kEnableNotificationScrollBarName,
+     flag_descriptions::kEnableNotificationScrollBarDescription, kOsCrOS,
+     FEATURE_VALUE_TYPE(ash::features::kNotificationScrollBar)},
     {"allow-touchpad-three-finger-click",
      flag_descriptions::kAllowTouchpadThreeFingerClickName,
      flag_descriptions::kAllowTouchpadThreeFingerClickDescription, kOsCrOS,

diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
@@ -620,6 +620,11 @@ const char kEnableNightLightDescription[] =
     "Enable the Night Light feature which controls the color temperature of "
     "the screen.";
 
+const char kEnableNotificationScrollBarName[] =
+    "Enable notification list scroll bar";
+const char kEnableNotificationScrollBarDescription[] =
+    "Enable the scroll bar of the notification list in Unified System Tray.";
+
 const char kEnableNupPrintingName[] = "Enable N-up printing";
 const char kEnableNupPrintingDescription[] =
     "Enable N-up printing in the print preview panel.";

diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
@@ -402,6 +402,9 @@ extern const char kEnableNewPrintPreviewDescription[];
 extern const char kEnableNightLightName[];
 extern const char kEnableNightLightDescription[];
 
+extern const char kEnableNotificationScrollBarName[];
+extern const char kEnableNotificationScrollBarDescription[];
+
 extern const char kEnableNupPrintingName[];
 extern const char kEnableNupPrintingDescription[];
 

diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
@@ -27430,6 +27430,7 @@ from previous Chrome versions.
   <int value="-2099035488" label="enable-data-reduction-proxy-bypass-warning"/>
   <int value="-2098610409" label="disable-lcd-text"/>
   <int value="-2098243118" label="OmniboxTailSuggestions:disabled"/>
+  <int value="-2097895488" label="NotificationScrollBar:enabled"/>
   <int value="-2097515669" label="disable-cast"/>
   <int value="-2091404586" label="TabStripKeyboardFocus:enabled"/>
   <int value="-2090484194" label="ContextualSearchUrlActions:disabled"/>
@@ -28192,6 +28193,7 @@ from previous Chrome versions.
   <int value="-621382525" label="VizDisplayCompositor:enabled"/>
   <int value="-620030047" label="CrosCompUpdates:disabled"/>
   <int value="-617452890" label="media-router"/>
+  <int value="-612633819" label="NotificationScrollBar:disabled"/>
   <int value="-612480090" label="FasterLocationReload:enabled"/>
   <int value="-610411643" label="enable-printer-app-search"/>
   <int value="-606898702" label="MaterialDesignSettings:disabled"/>