Screen Enumeration: Add a placeholder Screen.id to replace Screen.name

Use placeholder ordinal ids for now (0, 1, 2, ...); update tests.
TODO: generate per-origin UUIDs that reset when cookies are deleted

Test Screen.id values returned via window.getScreens() with:
 chrome://flags#enable-experimental-web-platform-features OR
 $ chrome --enable-blink-features=ScreenEnumeration
Try https://michaelwasserman.github.io/window-placement-demo

Bug: 994889
Test: Automated, Screen.id placeholder values
Change-Id: I0c5b18b92fef251211822f3473ea85472a7ee945
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2155113Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#761040}

content/browser/screen_enumeration/screen_enumeration_browsertest.cc

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/command_line.h"
+#include "base/strings/string_number_conversions.h"
 #include "build/build_config.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/test/browser_test_utils.h"
@@ -31,7 +32,7 @@ constexpr char kGetScreensScript[] = R"(
                     height: s.height,
                     internal: s.internal,
                     left: s.left,
-                    name: s.name,
+                    id: s.id,
                     orientation: s.orientation != null,
                     pixelDepth: s.pixelDepth,
                     primary: s.primary,
@@ -48,6 +49,7 @@ constexpr char kGetScreensScript[] = R"(
 base::ListValue GetExpectedScreens() {
   base::ListValue expected_screens;
   auto* screen = display::Screen::GetScreen();
+  size_t id = 0;
   for (const auto& d : screen->GetAllDisplays()) {
     base::DictionaryValue s;
     s.SetIntKey("availHeight", d.work_area().height());
@@ -58,7 +60,7 @@ base::ListValue GetExpectedScreens() {
     s.SetIntKey("height", d.bounds().height());
     s.SetBoolKey("internal", d.IsInternal());
     s.SetIntKey("left", d.bounds().x());
-    s.SetStringKey("name", "Generic Screen");
+    s.SetStringKey("id", base::NumberToString(id++));
     s.SetBoolKey("orientation", false);
     s.SetIntKey("pixelDepth", d.color_depth());
     s.SetBoolKey("primary", d.id() == screen->GetPrimaryDisplay().id());

third_party/blink/renderer/core/frame/screen.cc

@@ -173,11 +173,13 @@ void Screen::Trace(Visitor* visitor) {
 
 Screen::Screen(display::mojom::blink::DisplayPtr display,
                bool internal,
-               bool primary)
+               bool primary,
+               const String& id)
     : DOMWindowClient(static_cast<LocalFrame*>(nullptr)),
       display_(std::move(display)),
       internal_(internal),
-      primary_(primary) {}
+      primary_(primary),
+      id_(id) {}
 
 int Screen::left() const {
   if (display_) {
@@ -244,13 +246,13 @@ float Screen::scaleFactor() const {
   return GetScreenInfo(*frame).device_scale_factor;
 }
 
-const String Screen::name() const {
-  // TODO(http://crbug.com/994889): Implement this.
-  NOTIMPLEMENTED_LOG_ONCE();
+const String Screen::id() const {
   if (display_) {
     DCHECK(RuntimeEnabledFeatures::ScreenEnumerationEnabled());
-    return "Generic Screen";
+    return id_;
   }
+  // TODO(http://crbug.com/994889): Implement this for |window.screen|?
+  NOTIMPLEMENTED_LOG_ONCE();
   return String();
 }
 

third_party/blink/renderer/core/frame/screen.h

@@ -67,13 +67,14 @@ class CORE_EXPORT Screen final : public ScriptWrappable,
   // TODO(msw): Resolve different info sources, caching, and lifetimes.
   Screen(display::mojom::blink::DisplayPtr display,
          bool internal,
-         bool primary);
+         bool primary,
+         const String& id);
   int left() const;
   int top() const;
   bool internal() const;
   bool primary() const;
   float scaleFactor() const;
-  const String name() const;
+  const String id() const;
 
   // Not web-exposed; for internal usage only.
   static constexpr int64_t kInvalidDisplayId = -1;
@@ -92,6 +93,10 @@ class CORE_EXPORT Screen final : public ScriptWrappable,
   // value provided upon construction. This member is only valid for Screen
   // objects obtained via the experimental Screen Enumeration API.
   const base::Optional<bool> primary_;
+  // A web-exposed device id; it is a static value provided upon construction.
+  // This member is only valid for Screen objects obtained via the experimental
+  // Screen Enumeration API.
+  const String id_;
 };
 
 }  // namespace blink

third_party/blink/renderer/core/frame/screen.idl

@@ -49,5 +49,5 @@
     [RuntimeEnabled=ScreenEnumeration] readonly attribute boolean internal;
     [RuntimeEnabled=ScreenEnumeration] readonly attribute boolean primary;
     [RuntimeEnabled=ScreenEnumeration] readonly attribute float scaleFactor;
-    [RuntimeEnabled=ScreenEnumeration] readonly attribute DOMString name;
+    [RuntimeEnabled=ScreenEnumeration] readonly attribute DOMString id;
 };

third_party/blink/renderer/modules/screen_enumeration/global_screen_enumeration.cc

@@ -38,8 +38,12 @@ void DidGetDisplays(
   for (display::mojom::blink::DisplayPtr& backend_display : backend_displays) {
     const bool internal = backend_display->id == internal_id;
     const bool primary = backend_display->id == primary_id;
+    // TODO(http://crbug.com/994889): Implement temporary, generated per-origin
+    // unique device IDs that reset when cookies are deleted. See related:
+    // web_bluetooth_device_id.h, unguessable_token.h, and uuid.h
+    const String id = String::NumberToStringECMAScript(screens.size());
     screens.emplace_back(MakeGarbageCollected<Screen>(
-        std::move(backend_display), internal, primary));
+        std::move(backend_display), internal, primary, id));
   }
   resolver->Resolve(std::move(screens));
 }

third_party/blink/web_tests/external/wpt/screen_enumeration/getScreens.tentative.https.window.js

@@ -25,5 +25,5 @@ promise_test(async testCase => {
   assert_equals(typeof screens[0].primary, 'boolean');
   assert_equals(typeof screens[0].internal, 'boolean');
   assert_equals(typeof screens[0].scaleFactor, 'number');
-  assert_equals(typeof screens[0].name, 'string');
+  assert_equals(typeof screens[0].id, 'string');
 }, 'self.getScreens returns at least 1 Screen');
\ No newline at end of file

third_party/blink/web_tests/fast/dom/Window/property-access-on-cached-properties-after-frame-navigated-expected.txt

@@ -102,9 +102,9 @@ PASS window.cached_screen.availTop is 0
 PASS window.cached_screen.availWidth is 0
 PASS window.cached_screen.colorDepth is 0
 PASS window.cached_screen.height is 0
+PASS window.cached_screen.id is ''
 PASS window.cached_screen.internal is false
 PASS window.cached_screen.left is 0
-PASS window.cached_screen.name is ''
 PASS window.cached_screen.pixelDepth is 0
 PASS window.cached_screen.primary is false
 PASS window.cached_screen.scaleFactor is 0

third_party/blink/web_tests/fast/dom/Window/property-access-on-cached-properties-after-frame-removed-and-gced-expected.txt

@@ -102,9 +102,9 @@ PASS window.cached_screen.availTop is 0
 PASS window.cached_screen.availWidth is 0
 PASS window.cached_screen.colorDepth is 0
 PASS window.cached_screen.height is 0
+PASS window.cached_screen.id is ''
 PASS window.cached_screen.internal is false
 PASS window.cached_screen.left is 0
-PASS window.cached_screen.name is ''
 PASS window.cached_screen.pixelDepth is 0
 PASS window.cached_screen.primary is false
 PASS window.cached_screen.scaleFactor is 0

third_party/blink/web_tests/fast/dom/Window/property-access-on-cached-properties-after-frame-removed-expected.txt

@@ -102,9 +102,9 @@ PASS window.cached_screen.availTop is 0
 PASS window.cached_screen.availWidth is 0
 PASS window.cached_screen.colorDepth is 0
 PASS window.cached_screen.height is 0
+PASS window.cached_screen.id is ''
 PASS window.cached_screen.internal is false
 PASS window.cached_screen.left is 0
-PASS window.cached_screen.name is ''
 PASS window.cached_screen.pixelDepth is 0
 PASS window.cached_screen.primary is false
 PASS window.cached_screen.scaleFactor is 0

third_party/blink/web_tests/fast/dom/Window/property-access-on-cached-window-after-frame-navigated-expected.txt

@@ -233,9 +233,9 @@ PASS oldChildWindow.screen.availTop is newChildWindow.screen.availTop
 PASS oldChildWindow.screen.availWidth is newChildWindow.screen.availWidth
 PASS oldChildWindow.screen.colorDepth is newChildWindow.screen.colorDepth
 PASS oldChildWindow.screen.height is newChildWindow.screen.height
+PASS oldChildWindow.screen.id is newChildWindow.screen.id
 PASS oldChildWindow.screen.internal is newChildWindow.screen.internal
 PASS oldChildWindow.screen.left is newChildWindow.screen.left
-PASS oldChildWindow.screen.name is newChildWindow.screen.name
 PASS oldChildWindow.screen.orientation.angle is newChildWindow.screen.orientation.angle
 PASS oldChildWindow.screen.orientation.onchange is newChildWindow.screen.orientation.onchange
 PASS oldChildWindow.screen.orientation.type is newChildWindow.screen.orientation.type

third_party/blink/web_tests/fast/dom/Window/property-access-on-cached-window-after-frame-removed-and-gced-expected.txt

@@ -168,9 +168,9 @@ PASS childWindow.screen.availTop is 0
 PASS childWindow.screen.availWidth is 0
 PASS childWindow.screen.colorDepth is 0
 PASS childWindow.screen.height is 0
+PASS childWindow.screen.id is ''
 PASS childWindow.screen.internal is false
 PASS childWindow.screen.left is 0
-PASS childWindow.screen.name is ''
 PASS childWindow.screen.pixelDepth is 0
 PASS childWindow.screen.primary is false
 PASS childWindow.screen.scaleFactor is 0

third_party/blink/web_tests/fast/dom/Window/property-access-on-cached-window-after-frame-removed-expected.txt

@@ -168,9 +168,9 @@ PASS childWindow.screen.availTop is 0
 PASS childWindow.screen.availWidth is 0
 PASS childWindow.screen.colorDepth is 0
 PASS childWindow.screen.height is 0
+PASS childWindow.screen.id is ''
 PASS childWindow.screen.internal is false
 PASS childWindow.screen.left is 0
-PASS childWindow.screen.name is ''
 PASS childWindow.screen.pixelDepth is 0
 PASS childWindow.screen.primary is false
 PASS childWindow.screen.scaleFactor is 0

third_party/blink/web_tests/fast/dom/Window/window-appendages-cleared-expected.txt

@@ -30,9 +30,9 @@ PASS screen.availTop == "LEFTOVER" is false
 PASS screen.availWidth == "LEFTOVER" is false
 PASS screen.colorDepth == "LEFTOVER" is false
 PASS screen.height == "LEFTOVER" is false
+PASS screen.id == "LEFTOVER" is false
 PASS screen.internal == "LEFTOVER" is false
 PASS screen.left == "LEFTOVER" is false
-PASS screen.name == "LEFTOVER" is false
 PASS screen.orientation == "LEFTOVER" is false
 PASS screen.pixelDepth == "LEFTOVER" is false
 PASS screen.primary == "LEFTOVER" is false

third_party/blink/web_tests/webexposed/global-interface-listing-expected.txt

@@ -7889,9 +7889,9 @@ interface Screen
     getter availWidth
     getter colorDepth
     getter height
+    getter id
     getter internal
     getter left
-    getter name
     getter orientation
     getter pixelDepth
     getter primary