Don't flash black in classic, or in the body in aero

Maintains the clear in the title bar so that DWM doesn't flash white in the
non-client area. Don't clear the main content area despite the drawbacks for
resize on Win8 because the black clear on a new window is too noticable
because the NTP has a white background.

TEST=new windows, new menus, and resizing on win7 classic, aero, and win8
R=sky@chromium.org
BUG=177115,289095,290481

Review URL: https://chromiumcodereview.appspot.com/23842009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222978 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 1 insertions, 17 deletions

diff --git a/ui/views/win/hwnd_message_handler.cc b/ui/views/win/hwnd_message_handler.cc
index db09f9d..ba8f446 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -393,8 +393,7 @@ HWNDMessageHandler::HWNDMessageHandler(HWNDMessageHandlerDelegate* delegate)
       can_update_layered_window_(true),
       is_first_nccalc_(true),
       autohide_factory_(this),
-      id_generator_(0),
-      did_gdi_clear_(false) {
+      id_generator_(0) {
 }
 
 HWNDMessageHandler::~HWNDMessageHandler() {
@@ -1376,18 +1375,6 @@ void HWNDMessageHandler::OnEnterSizeMove() {
 }
 
 LRESULT HWNDMessageHandler::OnEraseBkgnd(HDC dc) {
-  if (!did_gdi_clear_) {
-    // This is necessary (at least on Win8) to avoid white flashing in the
-    // titlebar area around the minimize/maximize/close buttons.
-    HDC dc = GetDC(hwnd());
-    RECT client_rect;
-    GetClientRect(hwnd(), &client_rect);
-    HBRUSH brush = CreateSolidBrush(0);
-    FillRect(dc, &client_rect, brush);
-    DeleteObject(brush);
-    ReleaseDC(hwnd(), dc);
-    did_gdi_clear_ = true;
-  }
   // Needed to prevent resize flicker.
   return 1;
 }
diff --git a/ui/views/win/hwnd_message_handler.h b/ui/views/win/hwnd_message_handler.h
index 902eec3..5ff3ffd 100644
--- a/ui/views/win/hwnd_message_handler.h
+++ b/ui/views/win/hwnd_message_handler.h
@@ -476,9 +476,6 @@ class VIEWS_EXPORT HWNDMessageHandler :
   // Generates touch-ids for touch-events.
   ui::SequentialIDGenerator id_generator_;
 
-  // Necessary to avoid corruption on NC paint in Aero mode.
-  bool did_gdi_clear_;
-
   DISALLOW_COPY_AND_ASSIGN(HWNDMessageHandler);
 };