Hook up style invalidation for CSS Paint API.

third_party/WebKit/LayoutTests/csspaint/resources/test-runner-invalidation-logging.js

Index: third_party/WebKit/LayoutTests/csspaint/resources/test-runner-invalidation-logging.js
diff --git a/third_party/WebKit/LayoutTests/csspaint/resources/test-runner-invalidation-logging.js b/third_party/WebKit/LayoutTests/csspaint/resources/test-runner-invalidation-logging.js
new file mode 100644
index 0000000000000000000000000000000000000000..4035fd36948e78db3a25e99ce8b3e6ab5b166733
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/csspaint/resources/test-runner-invalidation-logging.js
@@ -0,0 +1,96 @@
+// Test runner for the paint worklet to test invalidation behaviour.
+//
+// Registers an async_test per test case, which:
+//  - Creates an element.
+//  - Invalidates the style of that element.
+//  - [worklet] Worklet code logs if it got the invalidation.
+//  - Asserts that it got the correct paint invalidation.
+//
+// Usage:
+// testRunnerInvalidationLogging('background-image', [
+//      { property: 'max-height', value: '100px' },
+//      { property: 'color', prevValue: '#00F', value: 'blue', noInvalidation: true },
+// ]);
+
+function testRunnerInvalidationLogging(imageType, tests) {
+    const keys = tests.map(function(obj) { return obj.property; });
+    const workletCode = 'const properties = ' + JSON.stringify(keys) + ';\n' + `
+        for (let i = 0; i < properties.length; i++) {
+            registerPaint('paint-' + i, class {
+                static get inputProperties() { return [properties[i]]; }
+                constructor() { this.hasPainted= false; }
+                paint(ctx, geom) {
+                    ctx.fillStyle = this.hasPainted ? 'green' : 'blue';
+                    ctx.fillRect(0, 0, geom.width, geom.height);
+                    if (this.hasPainted) {
+                        console.log('Successful invalidation for: ' + properties[i]);
+                    }
+                    this.hasPainted = true;
+                }
+            });
+        }
+    `;
+
+    paintWorklet.import(URL.createObjectURL(new Blob([workletCode]))).then(function() {
+        for (let i = 0; i < tests.length; i++) {
+            tests[i].paintName = 'paint-' + i;
+            registerTest(imageType, tests[i]);
+        }
+    });
+}
+
+function registerTest(imageType, test) {
+    const testName = test.property + ': ' + (test.prevValue || 'unset') + ' => ' + test.property + ': ' + (test.value || 'unset');
+
+    // We use a promise_test instead of a async_test as they run sequentially.
+    promise_test(function() {
+        return new Promise(function(resolve) {
+
+            const msg = ['\n\nTest case:', testName];
+            if (test.noInvalidation) {
+                msg.push('The worklet console should log nothing');
+            } else {
+                msg.push('The worklet console should log: \'Succussful invalidation for: ' + test.property + '\'');
+            }
+            console.log(msg.join('\n'));
+
+            // Create the test div.
+            const el = document.createElement('div');
+            if (test.prevValue) el.style.setProperty(test.property, test.prevValue);
+            el.style[imageType] = 'paint(' + test.paintName + ')';
+            document.body.appendChild(el);
+
+            runAfterLayoutAndPaint(function() {
+                if (window.internals)
+                    internals.startTrackingRepaints(document);
+
+                // Keep the BCR for the paint invalidation assertion, and invalidate paint.
+                const rect = el.getBoundingClientRect();
+                el.style.setProperty(test.property, test.value);
+
+                runAfterLayoutAndPaint(function() {
+                    // Check that the we got the correct paint invalidation.
+                    if (window.internals) {
+                        const layers = JSON.parse(internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_PAINT_INVALIDATIONS));
+                        const paintInvalidations = layers['children'][0]['paintInvalidations'];
+                        assert_equals(!!test.noInvalidation, !paintInvalidations);
+                        if (paintInvalidations) {
+                            assert_equals(1, paintInvalidations.length, 'There should be only one paint invalidation.');
+                            assert_array_equals(
+                                    [rect.left, rect.top, rect.width, rect.height],
+                                    paintInvalidations[0]['rect'],
+                                    'The paint invalidation should cover the entire element.');
+                        }
+                        internals.stopTrackingRepaints(document);
+                    }
+
+                    // Cleanup.
+                    document.body.removeChild(el);
+                    resolve();
+                });
+            });
+
+        });
+
+    }, testName);
+}