Add fromSurface optional parameter to devtools Page.CaptureScreenshot

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index 4afec65e2be43a227764516076b2ccd59f26758f..1220debf55e5f809070081f35606095cce576501 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -1453,6 +1453,17 @@ void RenderWidgetHostImpl::GetSnapshotFromBrowser(
   Send(new ViewMsg_ForceRedraw(GetRoutingID(), latency_info));
 }
 
+void RenderWidgetHostImpl::GetSurfaceSnapshotFromBrowser(
+    const GetSurfaceSnapshotFromBrowserCallback& callback) {
+  int id = next_browser_snapshot_id_++;
+
+  pending_surface_browser_snapshots_.insert(std::make_pair(id, callback));
+  ui::LatencyInfo latency_info;
+  latency_info.AddLatencyNumber(ui::WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT, 0,
+                                id);
+  Send(new ViewMsg_ForceRedraw(GetRoutingID(), latency_info));
+}
+
 const NativeWebKeyboardEvent*
     RenderWidgetHostImpl::GetLastKeyboardEvent() const {
   return input_router_->GetLastKeyboardEvent();
@@ -2360,26 +2371,64 @@ void RenderWidgetHostImpl::DidReceiveRendererFrame() {
 void RenderWidgetHostImpl::WindowSnapshotReachedScreen(int snapshot_id) {
   DCHECK(base::MessageLoopForUI::IsCurrent());
 
+  if (!pending_surface_browser_snapshots_.empty()) {
+    GetView()->CopyFromSurface(
+        gfx::Rect(), gfx::Size(),
+        base::Bind(&RenderWidgetHostImpl::OnSnapshotFromSurfaceReceived,
+                   weak_factory_.GetWeakPtr(), snapshot_id, 0),
+        kN32_SkColorType);
+  }
+
+  if (!pending_browser_snapshots_.empty()) {
 #if defined(OS_ANDROID)
-  // On Android, call sites should pass in the bounds with correct offset
-  // to capture the intended content area.
-  gfx::Rect snapshot_bounds(GetView()->GetViewBounds());
-  snapshot_bounds.Offset(0, GetView()->GetNativeView()->content_offset().y());
+    // On Android, call sites should pass in the bounds with correct offset
+    // to capture the intended content area.
+    gfx::Rect snapshot_bounds(GetView()->GetViewBounds());
+    snapshot_bounds.Offset(0, GetView()->GetNativeView()->content_offset().y());
 #else
-  gfx::Rect snapshot_bounds(GetView()->GetViewBounds().size());
+    gfx::Rect snapshot_bounds(GetView()->GetViewBounds().size());
 #endif
 
-  gfx::Image image;
-  if (ui::GrabViewSnapshot(GetView()->GetNativeView(), snapshot_bounds,
-                           &image)) {
-    OnSnapshotReceived(snapshot_id, image);
-    return;
+    gfx::Image image;
+    if (ui::GrabViewSnapshot(GetView()->GetNativeView(), snapshot_bounds,
+                             &image)) {
+      OnSnapshotReceived(snapshot_id, image);
+      return;
+    }
+
+    ui::GrabViewSnapshotAsync(
+        GetView()->GetNativeView(), snapshot_bounds,
+        base::Bind(&RenderWidgetHostImpl::OnSnapshotReceived,
+                   weak_factory_.GetWeakPtr(), snapshot_id));
   }
+}
 
-  ui::GrabViewSnapshotAsync(
-      GetView()->GetNativeView(), snapshot_bounds,
-      base::Bind(&RenderWidgetHostImpl::OnSnapshotReceived,
-                 weak_factory_.GetWeakPtr(), snapshot_id));
+void RenderWidgetHostImpl::OnSnapshotFromSurfaceReceived(
+    int snapshot_id,
+    int retry_count,
+    const SkBitmap& bitmap,
+    ReadbackResponse response) {
+  static const int kMaxRetries = 5;

[dgozman, 2017/03/08 19:21:36]

Why do we need retries?

[dvallet, 2017/03/09 06:19:47]

I copied this code from Eric's patch
https://codereview.chromium.org/2592983002/#ps40001. 

I'm guessing it mimics
https://cs.chromium.org/chromium/src/content/browser/devtools/protocol/page_h...

[Eric Seckler, 2017/03/09 09:55:22]

Yup, and it also mimics
https://cs.chromium.org/chromium/src/ui/snapshot/snapshot_aura.cc?l=53

It seems "common" that the copy may fail for some reason and retrying would
likely help. I don't know enough about readbacks to say why it might fail,
though.

+  if (response != READBACK_SUCCESS && retry_count < kMaxRetries) {
+    GetView()->CopyFromSurface(
+        gfx::Rect(), gfx::Size(),
+        base::Bind(&RenderWidgetHostImpl::OnSnapshotFromSurfaceReceived,
+                   weak_factory_.GetWeakPtr(), snapshot_id, retry_count + 1),
+        kN32_SkColorType);
+    return;
+  }
+  // Any pending snapshots with a lower ID than the one received are considered
+  // to be implicitly complete, and returned the same snapshot data.
+  PendingSnapshotFromSurfaceMap::iterator it =
+      pending_surface_browser_snapshots_.begin();
+  while (it != pending_surface_browser_snapshots_.end()) {
+    if (it->first <= snapshot_id) {
+      it->second.Run(bitmap);
+      pending_surface_browser_snapshots_.erase(it++);
+    } else {
+      ++it;
+    }
+  }
 }
 
 void RenderWidgetHostImpl::OnSnapshotReceived(int snapshot_id,