Relanding this with fixes for ash_unittests failures on the windows 8 builder.

Recreate and reinitialize the compositor when we receive the target HWND from the metro viewer process on Windows 8 ASH.

This ensures that the compositor paints on the correct surface.

Fixes a regression which occurred after the latest aura refactoring changes. This resulted in nothing painting
in Windows 8 ASH.

Ben's change to address the metro painting issue was reverted on Dec 20th due to ash_unittest crashes.

This fix works well with the ash_unittests and regular Chrome code path.

TBR'ing beng. Will address comments from him in a followup.

BUG=330179
R=ben@chromium.org, cpu@chromium.org
TBR=ben

Review URL: https://codereview.chromium.org/108893005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242910 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 14 insertions, 4 deletions

diff --git a/ui/aura/remote_root_window_host_win.cc b/ui/aura/remote_root_window_host_win.cc
index b8c14b7..18296f5 100644
--- a/ui/aura/remote_root_window_host_win.cc
+++ b/ui/aura/remote_root_window_host_win.cc
@@ -174,6 +174,10 @@ void RemoteRootWindowHostWin::Connected(IPC::Sender* host, HWND remote_window) {
   CHECK(host_ == NULL);
   host_ = host;
   remote_window_ = remote_window;
+  // Recreate the compositor for the target surface represented by the
+  // remote_window HWND.
+  CreateCompositor(remote_window_);
+  InitCompositor();
 }
 
 void RemoteRootWindowHostWin::Disconnected() {
diff --git a/ui/aura/window_tree_host.cc b/ui/aura/window_tree_host.cc
index 2702f2f..f29039c 100644
--- a/ui/aura/window_tree_host.cc
+++ b/ui/aura/window_tree_host.cc
@@ -82,15 +82,19 @@ RootWindowHost::~RootWindowHost() {
 }
 
 void RootWindowHost::InitHost() {
+  window()->Init(ui::LAYER_NOT_DRAWN);
+  InitCompositor();
+  UpdateRootWindowSize(GetBounds().size());
+  Env::GetInstance()->NotifyRootWindowInitialized(delegate_->AsRootWindow());
+  window()->Show();
+}
+
+void RootWindowHost::InitCompositor() {
   compositor_->SetScaleAndSize(GetDeviceScaleFactorFromDisplay(window()),
                                GetBounds().size());
-  window()->Init(ui::LAYER_NOT_DRAWN);
   compositor_->SetRootLayer(window()->layer());
   transformer_.reset(
       new SimpleRootWindowTransformer(window(), gfx::Transform()));
-  UpdateRootWindowSize(GetBounds().size());
-  Env::GetInstance()->NotifyRootWindowInitialized(delegate_->AsRootWindow());
-  window()->Show();
 }
 
 aura::Window* RootWindowHost::window() {
diff --git a/ui/aura/window_tree_host.h b/ui/aura/window_tree_host.h
index 8e1ddd0..ac18bfd 100644
--- a/ui/aura/window_tree_host.h
+++ b/ui/aura/window_tree_host.h
@@ -42,6 +42,8 @@ class AURA_EXPORT RootWindowHost {
 
   void InitHost();
 
+  void InitCompositor();
+
   // TODO(beng): these will become trivial accessors in a future CL.
   aura::Window* window();
   const aura::Window* window() const;