[Paint Preview] Add Accessibility Support

This adds a11y supoprt to the paint preview component. A follow-up CL
will add hooks to WebContentsAccessibility logic.

On capture, the AX tree is serialized to file. When the compositor is
initialzied, the AX tree is deserialized.

Bug: 1179326
Change-Id: Ib995dc3eaadeacec256daf6541e624d3fbf6f9e6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2698929
Commit-Queue: Mehran Mahmoudi <mahmoudi@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Reviewed-by: Tanya Gupta <tgupta@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#857905}

chrome/android/java/src/org/chromium/chrome/browser/app/flags/ChromeCachedFlags.java

@@ -14,6 +14,7 @@
 import org.chromium.chrome.browser.flags.CachedFieldTrialParameter;
 import org.chromium.chrome.browser.flags.ChromeFeatureList;
 import org.chromium.chrome.browser.page_annotations.PageAnnotationsServiceConfig;
+import org.chromium.chrome.browser.paint_preview.StartupPaintPreviewHelper;
 import org.chromium.chrome.browser.tab.state.ShoppingPersistedTabData;
 import org.chromium.chrome.browser.tasks.ConditionalTabStripUtils;
 import org.chromium.chrome.browser.tasks.ReturnToChromeExperimentsUtil;
@@ -98,6 +99,9 @@ public void cacheNativeFlags() {
                 ConditionalTabStripUtils.CONDITIONAL_TAB_STRIP_SESSION_TIME_MS,
                 PageAnnotationsServiceConfig.PAGE_ANNOTATIONS_BASE_URL,
                 ReturnToChromeExperimentsUtil.TAB_SWITCHER_ON_RETURN_MS,
+                ShoppingPersistedTabData.TIME_TO_LIVE_MS,
+                ShoppingPersistedTabData.DISPLAY_TIME_MS,
+                ShoppingPersistedTabData.STALE_TAB_THRESHOLD_SECONDS,
                 StartSurfaceConfiguration.HOME_BUTTON_ON_GRID_TAB_SWITCHER,
                 StartSurfaceConfiguration.NEW_SURFACE_FROM_HOME_BUTTON,
                 StartSurfaceConfiguration.OMNIBOX_FOCUSED_ON_NEW_TAB,
@@ -111,13 +115,11 @@ public void cacheNativeFlags() {
                 StartSurfaceConfiguration.TRENDY_ENDPOINT,
                 StartSurfaceConfiguration.TRENDY_FAILURE_MIN_PERIOD_MS,
                 StartSurfaceConfiguration.TRENDY_SUCCESS_MIN_PERIOD_MS,
+                StartupPaintPreviewHelper.ACCESSIBILITY_SUPPORT_PARAM,
                 TabContentManager.ALLOW_TO_REFETCH_TAB_THUMBNAIL_VARIATION,
                 TabUiFeatureUtilities.ENABLE_LAUNCH_BUG_FIX,
                 TabUiFeatureUtilities.ENABLE_LAUNCH_POLISH,
                 TabUiFeatureUtilities.ENABLE_SEARCH_CHIP,
-                ShoppingPersistedTabData.TIME_TO_LIVE_MS,
-                ShoppingPersistedTabData.DISPLAY_TIME_MS,
-                ShoppingPersistedTabData.STALE_TAB_THRESHOLD_SECONDS,
                 TabUiFeatureUtilities.ENABLE_PRICE_TRACKING,
                 TabUiFeatureUtilities.ENABLE_SEARCH_CHIP_ADAPTIVE,
                 TabUiFeatureUtilities.ZOOMING_MIN_MEMORY,

chrome/android/java/src/org/chromium/chrome/browser/paint_preview/StartupPaintPreviewHelper.java

@@ -12,6 +12,7 @@
 import org.chromium.base.ApplicationStatus;
 import org.chromium.base.Callback;
 import org.chromium.base.supplier.Supplier;
+import org.chromium.chrome.browser.flags.BooleanCachedFieldTrialParameter;
 import org.chromium.chrome.browser.flags.CachedFeatureFlags;
 import org.chromium.chrome.browser.flags.ChromeFeatureList;
 import org.chromium.chrome.browser.fullscreen.BrowserControlsManager;
@@ -35,6 +36,9 @@
  * Glue code for the Paint Preview show-on-startup feature.
  */
 public class StartupPaintPreviewHelper {
+    public static final BooleanCachedFieldTrialParameter ACCESSIBILITY_SUPPORT_PARAM =
+            new BooleanCachedFieldTrialParameter(ChromeFeatureList.PAINT_PREVIEW_SHOW_ON_STARTUP,
+                    "has_accessibility_support", false);
     /**
      * Tracks whether a paint preview should be shown on tab restore. We use this to only attempt
      * to display a paint preview on the first tab restoration that happens on Chrome startup when
@@ -126,8 +130,12 @@ private boolean preventShowOnRestore(Tab tab) {
      */
     public static void showPaintPreviewOnRestore(Tab tab) {
         if (!CachedFeatureFlags.isEnabled(ChromeFeatureList.PAINT_PREVIEW_SHOW_ON_STARTUP)
-                || !sShouldShowOnRestore
-                || ChromeAccessibilityUtil.get().isAccessibilityEnabled()) {
+                || !sShouldShowOnRestore) {
+            return;
+        }
+
+        if (ChromeAccessibilityUtil.get().isAccessibilityEnabled()
+                && !ACCESSIBILITY_SUPPORT_PARAM.getValue()) {
             return;
         }
 

chrome/browser/paint_preview/android/BUILD.gn

@@ -35,6 +35,7 @@ android_library("java") {
     "//chrome/browser/tab:java",
     "//chrome/browser/tabmodel:java",
     "//chrome/browser/ui/messages/android:java",
+    "//chrome/browser/util:java",
     "//components/browser_ui/styles/android:java",
     "//components/paint_preview/browser/android:java",
     "//components/paint_preview/common/proto:proto_java",

chrome/browser/paint_preview/android/java/src/org/chromium/chrome/browser/paint_preview/DemoPaintPreview.java

@@ -7,6 +7,7 @@
 import org.chromium.base.task.PostTask;
 import org.chromium.chrome.browser.tab.EmptyTabObserver;
 import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.util.ChromeAccessibilityUtil;
 import org.chromium.components.paintpreview.player.PlayerManager;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.content_public.browser.NavigationHandle;
@@ -105,6 +106,11 @@ public void onLinkClick(GURL url) {
         removePaintPreviewDemo();
     }
 
+    @Override
+    public boolean isAccessibilityEnabled() {
+        return ChromeAccessibilityUtil.get().isAccessibilityEnabled();
+    }
+
     private class DemoPaintPreviewTabObserver extends EmptyTabObserver {
         @Override
         public void onDidStartNavigation(Tab tab, NavigationHandle navigationHandle) {

chrome/browser/paint_preview/android/java/src/org/chromium/chrome/browser/paint_preview/StartupPaintPreview.java

@@ -23,6 +23,7 @@
 import org.chromium.chrome.browser.ui.messages.snackbar.Snackbar;
 import org.chromium.chrome.browser.ui.messages.snackbar.SnackbarManager;
 import org.chromium.chrome.browser.ui.messages.snackbar.SnackbarManagerProvider;
+import org.chromium.chrome.browser.util.ChromeAccessibilityUtil;
 import org.chromium.components.paintpreview.player.PlayerManager;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.content_public.browser.NavigationHandle;
@@ -284,6 +285,11 @@ public void onLinkClick(GURL url) {
         remove(ExitCause.LINK_CLICKED);
     }
 
+    @Override
+    public boolean isAccessibilityEnabled() {
+        return ChromeAccessibilityUtil.get().isAccessibilityEnabled();
+    }
+
     @VisibleForTesting
     TabObserver getTabObserverForTesting() {
         return mStartupTabObserver;

chrome/browser/paint_preview/android/javatests/src/org/chromium/chrome/browser/paint_preview/TabbedPaintPreviewTest.java

@@ -336,7 +336,7 @@ public static class TestCompositorDelegate implements PlayerCompositorDelegate {
                 parcel.setDataPosition(0);
                 UnguessableToken token = UnguessableToken.CREATOR.createFromParcel(parcel);
                 compositorListener.onCompositorReady(token, new UnguessableToken[] {token},
-                        new int[] {500, 500}, new int[] {0, 0}, new int[] {0}, null, null);
+                        new int[] {500, 500}, new int[] {0, 0}, new int[] {0}, null, null, 0);
             }, 250);
         }
 
@@ -408,5 +408,10 @@ public void onPullToRefresh() {}
 
         @Override
         public void onLinkClick(GURL url) {}
+
+        @Override
+        public boolean isAccessibilityEnabled() {
+            return false;
+        }
     }
 }

chrome/browser/paint_preview/services/paint_preview_tab_service.cc

@@ -17,7 +17,9 @@
 #include "chrome/browser/paint_preview/services/paint_preview_tab_service_file_mixin.h"
 #include "components/paint_preview/browser/file_manager.h"
 #include "components/paint_preview/browser/warm_compositor.h"
+#include "content/public/browser/browser_accessibility_state.h"
 #include "content/public/browser/render_process_host.h"
+#include "ui/accessibility/ax_mode.h"
 #include "ui/gfx/geometry/rect.h"
 
 #if defined(OS_ANDROID)
@@ -54,6 +56,18 @@ int TabIdFromDirectoryKey(const DirectoryKey& key) {
 
 }  // namespace
 
+PaintPreviewTabService::TabServiceTask::TabServiceTask(
+    int tab_id,
+    const DirectoryKey& key,
+    int frame_tree_node_id,
+    content::GlobalFrameRoutingId frame_routing_id)
+    : tab_id_(tab_id),
+      key_(key),
+      frame_tree_node_id_(frame_tree_node_id),
+      frame_routing_id_(frame_routing_id) {}
+
+PaintPreviewTabService::TabServiceTask::~TabServiceTask() = default;
+
 PaintPreviewTabService::PaintPreviewTabService(
     std::unique_ptr<PaintPreviewFileMixin> file_mixin,
     std::unique_ptr<PaintPreviewPolicy> policy,
@@ -112,16 +126,27 @@ void PaintPreviewTabService::CaptureTab(int tab_id,
   contents->IncrementCapturerCount(gfx::Size(), true);
 
   auto file_manager = GetFileMixin()->GetFileManager();
+
   auto key = file_manager->CreateKey(tab_id);
+  auto it = tasks_.emplace(
+      tab_id, std::make_unique<TabServiceTask>(
+                  tab_id, key, contents->GetMainFrame()->GetFrameTreeNodeId(),
+                  contents->GetMainFrame()->GetGlobalFrameRoutingId()));
+  if (!it.second) {
+    std::move(callback).Run(Status::kCaptureInProgress);
+    return;
+  }
+  it.first->second->SetCallback(std::move(callback).Then(
+      base::BindOnce(&PaintPreviewTabService::DeleteTask,
+                     weak_ptr_factory_.GetWeakPtr(), tab_id)));
+
   GetFileMixin()->GetTaskRunner()->PostTaskAndReplyWithResult(
       FROM_HERE,
       base::BindOnce(&FileManager::CreateOrGetDirectory,
                      GetFileMixin()->GetFileManager(), key, true),
       base::BindOnce(&PaintPreviewTabService::CaptureTabInternal,
-                     weak_ptr_factory_.GetWeakPtr(), tab_id, key,
-                     contents->GetMainFrame()->GetFrameTreeNodeId(),
-                     contents->GetMainFrame()->GetGlobalFrameRoutingId(),
-                     std::move(callback)));
+                     weak_ptr_factory_.GetWeakPtr(),
+                     it.first->second->GetWeakPtr()));
 }
 
 void PaintPreviewTabService::TabClosed(int tab_id) {
@@ -214,6 +239,10 @@ PaintPreviewTabService::GetPathAndroid(JNIEnv* env) {
 }
 #endif  // defined(OS_ANDROID)
 
+void PaintPreviewTabService::DeleteTask(int tab_id) {
+  tasks_.erase(tab_id);
+}
+
 void PaintPreviewTabService::InitializeCache(
     const base::flat_set<DirectoryKey>& in_use_keys) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
@@ -227,26 +256,40 @@ void PaintPreviewTabService::InitializeCache(
 }
 
 void PaintPreviewTabService::CaptureTabInternal(
-    int tab_id,
-    const DirectoryKey& key,
-    int frame_tree_node_id,
-    content::GlobalFrameRoutingId frame_routing_id,
-    FinishedCallback callback,
+    base::WeakPtr<TabServiceTask> task,
     const base::Optional<base::FilePath>& file_path) {
+  if (!task) {
+    return;
+  }
+
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   if (!file_path.has_value()) {
-    std::move(callback).Run(Status::kDirectoryCreationFailed);
+    task->OnCaptured(Status::kDirectoryCreationFailed);
     return;
   }
   auto* contents =
-      content::WebContents::FromFrameTreeNodeId(frame_tree_node_id);
-  auto* rfh = content::RenderFrameHost::FromID(frame_routing_id);
+      content::WebContents::FromFrameTreeNodeId(task->frame_tree_node_id());
+  auto* rfh = content::RenderFrameHost::FromID(task->frame_routing_id());
   if (!contents || !rfh || contents->IsBeingDestroyed() ||
       contents->GetMainFrame() != rfh || !rfh->IsCurrent() ||
       !rfh->IsRenderFrameCreated() || !rfh->IsRenderFrameLive()) {
-    std::move(callback).Run(Status::kWebContentsGone);
+    task->OnCaptured(Status::kWebContentsGone);
     return;
   }
+  if (content::BrowserAccessibilityState::GetInstance()
+          ->IsAccessibleBrowser()) {
+    task->SetWaitForAccessibility();
+    contents->RequestAXTreeSnapshot(
+        base::BindOnce(&PaintPreviewFileMixin::WriteAXTreeUpdate,
+                       GetFileMixin()->GetWeakPtr(), task->key(),
+                       base::BindOnce(&PaintPreviewTabService::OnAXTreeWritten,
+                                      weak_ptr_factory_.GetWeakPtr(), task)),
+        ui::kAXModeWebContentsOnly,
+        /* exclude_offscreen= */ false,
+        /* max_nodes= */ 5000,
+        /* timeout= */ {});
+  }
+
   CaptureParams capture_params;
   capture_params.web_contents = contents;
   capture_params.render_frame_host = rfh;
@@ -255,50 +298,61 @@ void PaintPreviewTabService::CaptureTabInternal(
   capture_params.clip_rect = gfx::Rect();
   capture_params.capture_links = true;
   capture_params.max_per_capture_size = kMaxPerCaptureSizeBytes;
-  CapturePaintPreview(
-      capture_params,
-      base::BindOnce(&PaintPreviewTabService::OnCaptured,
-                     weak_ptr_factory_.GetWeakPtr(), tab_id, key,
-                     frame_tree_node_id, std::move(callback)));
+  CapturePaintPreview(capture_params,
+                      base::BindOnce(&PaintPreviewTabService::OnCaptured,
+                                     weak_ptr_factory_.GetWeakPtr(), task));
+}
+
+void PaintPreviewTabService::OnAXTreeWritten(base::WeakPtr<TabServiceTask> task,
+                                             bool result) {
+  if (task) {
+    task->OnAXTreeWritten(result);
+  }
 }
 
 void PaintPreviewTabService::OnCaptured(
-    int tab_id,
-    const DirectoryKey& key,
-    int frame_tree_node_id,
-    FinishedCallback callback,
+    base::WeakPtr<TabServiceTask> task,
     PaintPreviewBaseService::CaptureStatus status,
     std::unique_ptr<CaptureResult> result) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+  if (!task) {
+    return;
+  }
+
   auto* web_contents =
-      content::WebContents::FromFrameTreeNodeId(frame_tree_node_id);
+      content::WebContents::FromFrameTreeNodeId(task->frame_tree_node_id());
   if (web_contents)
     web_contents->DecrementCapturerCount(true);
 
   if (status != PaintPreviewBaseService::CaptureStatus::kOk ||
       !result->capture_success) {
-    std::move(callback).Run(Status::kCaptureFailed);
+    task->OnCaptured(Status::kCaptureFailed);
     return;
   }
   auto file_manager = GetFileMixin()->GetFileManager();
   GetFileMixin()->GetTaskRunner()->PostTaskAndReplyWithResult(
       FROM_HERE,
       base::BindOnce(&FileManager::SerializePaintPreviewProto,
-                     GetFileMixin()->GetFileManager(), key, result->proto,
-                     true),
+                     GetFileMixin()->GetFileManager(), task->key(),
+                     result->proto, true),
       base::BindOnce(&PaintPreviewTabService::OnFinished,
-                     weak_ptr_factory_.GetWeakPtr(), tab_id,
-                     std::move(callback)));
+                     weak_ptr_factory_.GetWeakPtr(), task));
 }
 
-void PaintPreviewTabService::OnFinished(int tab_id,
-                                        FinishedCallback callback,
+void PaintPreviewTabService::OnFinished(base::WeakPtr<TabServiceTask> task,
                                         bool success) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
-  if (success)
+  if (!task) {
+    return;
+  }
+  int tab_id = task->tab_id();
+
+  if (success) {
     captured_tab_ids_.insert(tab_id);
-  std::move(callback).Run(success ? Status::kOk
-                                  : Status::kProtoSerializationFailed);
+  }
+  // WARNING: `task` may be invalidated by this call.
+  task->OnCaptured(success ? Status::kOk : Status::kProtoSerializationFailed);
+
   auto file_manager = GetFileMixin()->GetFileManager();
   GetFileMixin()->GetTaskRunner()->PostTaskAndReplyWithResult(
       FROM_HERE,
@@ -350,8 +404,8 @@ void PaintPreviewTabService::RunAudit(
   keys_to_delete.resize(it - keys_to_delete.begin());
 
   // The performance of this is poor (O(n) per removal). However,
-  // |keys_to_delete| should normally be 0 or small and this is only run once at
-  // startup.
+  // |keys_to_delete| should normally be 0 or small and this is only run once
+  // at startup.
   for (const auto& key : keys_to_delete)
     captured_tab_ids_.erase(TabIdFromDirectoryKey(key));