cros: add ash-enable-persistent-window-bounds switch

changes:
Add a switch to make the feature dev behind the flag.

Bug: 805046
Test: unit_tests --gtest_filter=AboutFlagsHistogramTest*
Change-Id: I1b63060cf6b08557d94447b4a87f9ab07b192e1c
Reviewed-on: https://chromium-review.googlesource.com/890633Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Commit-Queue: Qiang Xu <warx@google.com>
Cr-Commit-Position: refs/heads/master@{#532546}

ash/public/cpp/ash_switches.cc

@@ -75,6 +75,11 @@ const char kAshEnableNightLight[] = "ash-enable-night-light";
 const char kAshEnablePaletteOnAllDisplays[] =
     "ash-enable-palette-on-all-displays";
 
+// Enables persistent window bounds in multi-displays scenario.
+// TODO(warx): Remove this once the feature is launched. crbug.com/805046.
+const char kAshEnablePersistentWindowBounds[] =
+    "ash-enable-persistent-window-bounds";
+
 // Enables the sidebar.
 const char kAshSidebarEnabled[] = "enable-ash-sidebar";
 const char kAshSidebarDisabled[] = "disable-ash-sidebar";

ash/public/cpp/ash_switches.h

@@ -32,6 +32,7 @@ ASH_PUBLIC_EXPORT extern const char kAshEnableMagnifierKeyScroller[];
 ASH_PUBLIC_EXPORT extern const char kAshEnableNewOverviewUi[];
 ASH_PUBLIC_EXPORT extern const char kAshEnableNightLight[];
 ASH_PUBLIC_EXPORT extern const char kAshEnablePaletteOnAllDisplays[];
+ASH_PUBLIC_EXPORT extern const char kAshEnablePersistentWindowBounds[];
 ASH_PUBLIC_EXPORT extern const char kAshEnableScaleSettingsTray[];
 ASH_PUBLIC_EXPORT extern const char kAshEnableTabletMode[];
 ASH_PUBLIC_EXPORT extern const char kAshEnableWaylandServer[];

chrome/browser/about_flags.cc

@@ -3606,6 +3606,11 @@ const FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kAshDisableLoginDimAndBlurName,
      flag_descriptions::kAshDisableLoginDimAndBlurDescription, kOsCrOS,
      SINGLE_DISABLE_VALUE_TYPE(ash::switches::kAshDisableLoginDimAndBlur)},
+
+    {"ash-enable-persistent-window-bounds",
+     flag_descriptions::kAshEnablePersistentWindowBoundsName,
+     flag_descriptions::kAshEnablePersistentWindowBoundsDescription, kOsCrOS,
+     SINGLE_VALUE_TYPE(ash::switches::kAshEnablePersistentWindowBounds)},
 #endif  // OS_CHROMEOS
 
     {"clipboard-content-setting",

chrome/browser/flag_descriptions.cc

@@ -2926,6 +2926,11 @@ const char kAshEnableMirroredScreenDescription[] =
     "Enable the mirrored screen mode. This mode flips the screen image "
     "horizontally.";
 
+const char kAshEnablePersistentWindowBoundsName[] =
+    "Enable persistent window bounds in multi-displays scenario.";
+const char kAshEnablePersistentWindowBoundsDescription[] =
+    "Enable persistent window bounds in multi-displays scenario.";
+
 const char kAshShelfColorName[] = "Shelf color in Chrome OS system UI";
 const char kAshShelfColorDescription[] =
     "Enables/disables the shelf color to be a derived from the wallpaper. The "

chrome/browser/flag_descriptions.h

@@ -1805,6 +1805,9 @@ extern const char kAshEnableKeyboardShortcutViewerDescription[];
 extern const char kAshEnableMirroredScreenName[];
 extern const char kAshEnableMirroredScreenDescription[];
 
+extern const char kAshEnablePersistentWindowBoundsName[];
+extern const char kAshEnablePersistentWindowBoundsDescription[];
+
 extern const char kAshShelfColorName[];
 extern const char kAshShelfColorDescription[];
 

tools/metrics/histograms/enums.xml

@@ -25429,6 +25429,7 @@ from previous Chrome versions.
   <int value="-1613583483" label="UseNewAcceptLanguageHeader:enabled"/>
   <int value="-1611305202" label="KeepPrefetchedContentSuggestions:disabled"/>
   <int value="-1607691647" label="MojoVideoEncodeAccelerator:disabled"/>
+  <int value="-1607297082" label="ash-enable-persistent-window-bounds"/>
   <int value="-1605567628" label="disable-overlay-scrollbar"/>
   <int value="-1604051051" label="SpecialLocale:disabled"/>
   <int value="-1603404046" label="V8VmFuture:disabled"/>