Introduce kDisplayLayoutPreview flag

Bug: 1070122
Change-Id: I867303003042b9129a1f6bbcf203aa41d29f6615
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2274155
Commit-Queue: Bailey Berro <baileyberro@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#790241}

chrome/browser/about_flags.cc

@@ -4938,6 +4938,11 @@ const FeatureEntry kFeatureEntries[] = {
     {"display-identification", flag_descriptions::kDisplayIdentificationName,
      flag_descriptions::kDisplayIdentificationDescription, kOsCrOS,
      FEATURE_VALUE_TYPE(ash::features::kDisplayIdentification)},
+
+    {"display-alignment-assistance",
+     flag_descriptions::kDisplayAlignmentAssistanceName,
+     flag_descriptions::kDisplayAlignmentAssistanceDescription, kOsCrOS,
+     FEATURE_VALUE_TYPE(ash::features::kDisplayAlignAssist)},
 #endif  // OS_CHROMEOS
 
     {"autofill-off-no-server-data",

chrome/browser/flag-metadata.json

@@ -927,6 +927,11 @@
     "owners": [ "alemate" ],
     "expiry_milestone": 80
   },
+  {
+    "name": "display-alignment-assistance",
+    "owners": [ "baileyberro", "cros-peripherals@google.com" ],
+    "expiry_milestone": 89
+  },
   {
     "name": "display-identification",
     "owners": [ "baileyberro", "cros-peripherals@google.com" ],

chrome/browser/flag_descriptions.cc

@@ -3527,6 +3527,13 @@ const char kDisableExplicitDmaFencesDescription[] =
     "Always rely on implicit syncrhonization between GPU and display "
     "controller instead of using dma-fences explcitily when available.";
 
+const char kDisplayAlignmentAssistanceName[] =
+    "Enable Display Alignment Assistance";
+const char kDisplayAlignmentAssistanceDescription[] =
+    "Show indicators on shared edges of the displays when user is "
+    "attempting to move their mouse over to another display. Show preview "
+    "indicators when the user is moving a display in display layouts.";
+
 const char kDisplayIdentificationName[] =
     "Enable display identification highlight";
 const char kDisplayIdentificationDescription[] =

chrome/browser/flag_descriptions.h

@@ -2042,6 +2042,9 @@ extern const char kDisableCryptAuthV1DeviceSyncDescription[];
 extern const char kDisableExplicitDmaFencesName[];
 extern const char kDisableExplicitDmaFencesDescription[];
 
+extern const char kDisplayAlignmentAssistanceName[];
+extern const char kDisplayAlignmentAssistanceDescription[];
+
 extern const char kDisplayIdentificationName[];
 extern const char kDisplayIdentificationDescription[];
 

tools/metrics/histograms/enums.xml

@@ -41478,6 +41478,7 @@ from previous Chrome versions.
   <int value="-204355195" label="secondary-ui-md"/>
   <int value="-203968600" label="SyncSupportSecondaryAccount:disabled"/>
   <int value="-202007318" label="AndroidAIAFetching:enabled"/>
+  <int value="-201633741" label="DisplayAlignAssist:enabled"/>
   <int value="-200805659" label="ContextualSuggestionsButton:enabled"/>
   <int value="-199690952" label="PageInfoV2:enabled"/>
   <int value="-196110497" label="force-text-direction"/>
@@ -42276,6 +42277,7 @@ from previous Chrome versions.
   <int value="679931272" label="DcheckIsFatal:enabled"/>
   <int value="680070635"
       label="enable-fullscreen-handwriting-virtual-keyboard:disabled"/>
+  <int value="680300401" label="DisplayAlignAssist:disabled"/>
   <int value="681622885" label="FullscreenExitUI:enabled"/>
   <int value="682549212" label="ash-enable-cursor-motion-blur"/>
   <int value="683013217" label="AllowPopupsDuringPageUnload:disabled"/>