aura: Make WebContents VISIBLE when shown in Alt-Tab view on ChromeOS.

Today, WebContents::GetVisibility() returns HIDDEN for a tab that is in
a minimized window shown in the Alt-Tab view on ChromeOS. This is
because content::WebContents::GetVisibility() indicates the visibility
of the aura::Window, and isn't affected by the mirroring functionnality
used by the Alt-Tab view.

Unfortunately, the fact that WebContents::GetVisibility() returns
HIDDEN makes TabManager think that the tab is eligible for freezing and
discarding (freezing or discarding a tab in Alt-Tab breaks the live
view functionnality). TabManager could check by itself whether the
WebContents IsBeingCaptured(), but instead of requiring that every
call to WebContents::GetVisibility() be accompanied to a check to
IsBeingCaptured(), we believe it's better to return VISIBLE from
GetVisibility() when a tab is displayed in Alt-Tab view.

Bug: 876103
Change-Id: I01c07858bcae3038577bac1408c67eb72fe08e0c
Reviewed-on: https://chromium-review.googlesource.com/1191862Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: François Doray <fdoray@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587711}

content/browser/web_contents/web_contents_view_aura.cc

@@ -422,12 +422,8 @@ class WebContentsViewAura::WindowObserver
   void OnWindowPropertyChanged(aura::Window* window,
                                const void* key,
                                intptr_t old) override {
-    if (key != aura::client::kMirroringEnabledKey)
-      return;
-    if (window->GetProperty(aura::client::kMirroringEnabledKey))
-      view_->web_contents_->IncrementCapturerCount(gfx::Size());
-    else
-      view_->web_contents_->DecrementCapturerCount();
+    if (key == aura::client::kMirroringEnabledKey)
+      view_->UpdateWebContentsVisibility();
   }
 
   // Overridden WindowTreeHostObserver:
@@ -761,6 +757,25 @@ void WebContentsViewAura::CreateAuraWindow(aura::Window* context) {
     window_observer_.reset(new WindowObserver(this));
 }
 
+void WebContentsViewAura::UpdateWebContentsVisibility() {
+  web_contents_->UpdateWebContentsVisibility(GetVisibility());
+}
+
+Visibility WebContentsViewAura::GetVisibility() const {
+  // aura::client::kMirroringEnabledKey indicates that the window is displayed
+  // in Alt-Tab view on ChromeOS.
+  if (window_->occlusion_state() == aura::Window::OcclusionState::VISIBLE ||
+      window_->GetProperty(aura::client::kMirroringEnabledKey)) {
+    return Visibility::VISIBLE;
+  }
+
+  if (window_->occlusion_state() == aura::Window::OcclusionState::OCCLUDED)
+    return Visibility::OCCLUDED;
+
+  DCHECK_EQ(window_->occlusion_state(), aura::Window::OcclusionState::HIDDEN);
+  return Visibility::HIDDEN;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // WebContentsViewAura, WebContentsView implementation:
 
@@ -1100,12 +1115,7 @@ void WebContentsViewAura::OnWindowTargetVisibilityChanged(bool visible) {
 
 void WebContentsViewAura::OnWindowOcclusionChanged(
     aura::Window::OcclusionState occlusion_state) {
-  web_contents_->UpdateWebContentsVisibility(
-      occlusion_state == aura::Window::OcclusionState::VISIBLE
-          ? content::Visibility::VISIBLE
-          : (occlusion_state == aura::Window::OcclusionState::OCCLUDED
-                 ? content::Visibility::OCCLUDED
-                 : content::Visibility::HIDDEN));
+  UpdateWebContentsVisibility();
 }
 
 bool WebContentsViewAura::HasHitTestMask() const {

content/browser/web_contents/web_contents_view_aura.h

@@ -18,6 +18,7 @@
 #include "content/common/buildflags.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/global_routing_id.h"
+#include "content/public/browser/visibility.h"
 #include "ui/aura/client/drag_drop_delegate.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
@@ -97,6 +98,12 @@ class CONTENT_EXPORT WebContentsViewAura
   // Called from CreateView() to create |window_|.
   void CreateAuraWindow(aura::Window* context);
 
+  // Computes the view's visibility updates the WebContents accordingly.
+  void UpdateWebContentsVisibility();
+
+  // Computes the view's visibility.
+  Visibility GetVisibility() const;
+
   // Overridden from WebContentsView:
   gfx::NativeView GetNativeView() const override;
   gfx::NativeView GetContentNativeView() const override;

content/browser/web_contents/web_contents_view_aura_unittest.cc

@@ -7,12 +7,14 @@
 #include <memory>
 
 #include "base/command_line.h"
+#include "base/macros.h"
 #include "base/test/scoped_command_line.h"
 #include "base/test/scoped_feature_list.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/common/content_features.h"
 #include "content/public/test/test_renderer_host.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "ui/aura/client/aura_constants.h"
 #include "ui/aura/test/test_windows.h"
 #include "ui/aura/window.h"
 #include "ui/display/display_switches.h"
@@ -25,22 +27,38 @@ constexpr gfx::Rect kBounds = gfx::Rect(0, 0, 20, 20);
 }  // namespace
 
 class WebContentsViewAuraTest : public RenderViewHostTestHarness {
- public:
+ protected:
   WebContentsViewAuraTest() = default;
   ~WebContentsViewAuraTest() override = default;
 
   void SetUp() override {
     RenderViewHostTestHarness::SetUp();
     root_window()->SetBounds(kBounds);
-    web_contents()->GetNativeView()->SetBounds(kBounds);
-    web_contents()->GetNativeView()->Show();
-    root_window()->AddChild(web_contents()->GetNativeView());
+    GetNativeView()->SetBounds(kBounds);
+    GetNativeView()->Show();
+    root_window()->AddChild(GetNativeView());
+    other_window_.reset(aura::test::CreateTestWindowWithDelegateAndType(
+        nullptr, aura::client::WINDOW_TYPE_NORMAL, 0, kBounds, root_window(),
+        false));
+  }
+
+  void TearDown() override {
+    other_window_.reset();
+    RenderViewHostTestHarness::TearDown();
   }
 
   WebContentsViewAura* view() {
     WebContentsImpl* contents = static_cast<WebContentsImpl*>(web_contents());
     return static_cast<WebContentsViewAura*>(contents->GetView());
   }
+
+  aura::Window* GetNativeView() { return web_contents()->GetNativeView(); }
+
+  // |other_window| occludes |web_contents()| when it's shown.
+  std::unique_ptr<aura::Window> other_window_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(WebContentsViewAuraTest);
 };
 
 TEST_F(WebContentsViewAuraTest, EnableDisableOverscroll) {
@@ -63,17 +81,40 @@ TEST_F(WebContentsViewAuraTest, OccludeView) {
   base::test::ScopedFeatureList scoped_feature_list;
   scoped_feature_list.InitAndEnableFeature(features::kWebContentsOcclusion);
 
-  // |other_window| occludes |web_contents()| when it's shown.
-  std::unique_ptr<aura::Window> other_window(
-      aura::test::CreateTestWindowWithDelegateAndType(
-          nullptr, aura::client::WINDOW_TYPE_NORMAL, 0, kBounds, root_window(),
-          false));
-
   EXPECT_EQ(web_contents()->GetVisibility(), Visibility::VISIBLE);
-  other_window->Show();
+  other_window_->Show();
   EXPECT_EQ(web_contents()->GetVisibility(), Visibility::OCCLUDED);
-  other_window->Hide();
+  other_window_->Hide();
   EXPECT_EQ(web_contents()->GetVisibility(), Visibility::VISIBLE);
 }
 
+TEST_F(WebContentsViewAuraTest, MirroringEnabledForHiddenView) {
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::VISIBLE);
+  root_window()->Hide();
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::HIDDEN);
+  GetNativeView()->SetProperty(aura::client::kMirroringEnabledKey, true);
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::VISIBLE);
+  GetNativeView()->SetProperty(aura::client::kMirroringEnabledKey, false);
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::HIDDEN);
+  root_window()->Show();
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::VISIBLE);
+  GetNativeView()->SetProperty(aura::client::kMirroringEnabledKey, true);
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::VISIBLE);
+  GetNativeView()->SetProperty(aura::client::kMirroringEnabledKey, false);
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::VISIBLE);
+}
+
+TEST_F(WebContentsViewAuraTest, MirroringEnabledForOccludedView) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeature(features::kWebContentsOcclusion);
+
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::VISIBLE);
+  other_window_->Show();
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::OCCLUDED);
+  GetNativeView()->SetProperty(aura::client::kMirroringEnabledKey, true);
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::VISIBLE);
+  GetNativeView()->SetProperty(aura::client::kMirroringEnabledKey, false);
+  EXPECT_EQ(web_contents()->GetVisibility(), content::Visibility::OCCLUDED);
+}
+
 }  // namespace content