Add occlusion support to WebContentsImpl and RenderWidgetHostView

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index f9ba939d844ad18acc9ababcfad18f576437144e..ba1faa7ae09dbe1d5f53f4bec8bec92123c767cf 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -925,6 +925,9 @@ void WebContentsImpl::IncrementCapturerCount(const gfx::Size& capture_size) {
     preferred_size_for_capture_ = capture_size;
     OnPreferredSizeChanged(preferred_size_);
   }
+
+  // Ensure that all views are un-occluded before capture begins.
+  WasUnOccluded();

[ccameron, 2015/01/16 19:01:11]

I think there's a bug here where we will get into an inconsistent state if we
try to capture while hidden (perhaps that isn't possible?). I'm going to clean
up the WasHidden/WasShown code in a future patch (future b/c it will have
effects on non-Mac platforms).

 }
 
 void WebContentsImpl::DecrementCapturerCount() {
@@ -1025,14 +1028,11 @@ base::TimeTicks WebContentsImpl::GetLastActiveTime() const {
 void WebContentsImpl::WasShown() {
   controller_.SetActive(true);
 
-  std::set<RenderWidgetHostView*> widgets = GetRenderWidgetHostViewsInTree();
-  for (std::set<RenderWidgetHostView*>::iterator iter = widgets.begin();
-       iter != widgets.end();
-       iter++) {
-    if (*iter) {
-      (*iter)->Show();
+  for (RenderWidgetHostView* view : GetRenderWidgetHostViewsInTree()) {
+    if (view) {
+      view->Show();
 #if defined(OS_MACOSX)
-      (*iter)->SetActive(true);
+      view->SetActive(true);
 #endif
     }
   }
@@ -1066,12 +1066,9 @@ void WebContentsImpl::WasHidden() {
     // removes the |GetRenderViewHost()|; then when we actually destroy the
     // window, OnWindowPosChanged() notices and calls WasHidden() (which
     // calls us).
-    std::set<RenderWidgetHostView*> widgets = GetRenderWidgetHostViewsInTree();
-    for (std::set<RenderWidgetHostView*>::iterator iter = widgets.begin();
-         iter != widgets.end();
-         iter++) {
-      if (*iter)
-        (*iter)->Hide();
+    for (RenderWidgetHostView* view : GetRenderWidgetHostViewsInTree()) {
+      if (view)
+        view->Hide();
     }
 
     // Release any video power save blockers held as video is not visible.
@@ -1083,6 +1080,23 @@ void WebContentsImpl::WasHidden() {
   should_normally_be_visible_ = false;
 }
 
+void WebContentsImpl::WasOccluded() {
+  if (capturer_count_ > 0)
+    return;
+
+  for (RenderWidgetHostView* view : GetRenderWidgetHostViewsInTree()) {
+    if (view)
+      view->WasOccluded();
+  }
+}
+
+void WebContentsImpl::WasUnOccluded() {
+  for (RenderWidgetHostView* view : GetRenderWidgetHostViewsInTree()) {
+    if (view)
+      view->WasUnOccluded();
+  }
+}
+
 bool WebContentsImpl::NeedToFireBeforeUnload() {
   // TODO(creis): Should we fire even for interstitial pages?
   return WillNotifyDisconnection() &&