Some speculative fixes for UI test flakiness.

- make the window update locking use window visibility instead of WM_SETREDRAW. I believe WM_SETREDRAW is causing the window to become visible during tests.
- potential crashes caused by NULL TabcontentsDelegates.

TBR=sky
Review URL: http://codereview.chromium.org/10674

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@5335 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 15 insertions, 11 deletions

diff --git a/chrome/browser/views/tabs/dragged_tab_controller.cc b/chrome/browser/views/tabs/dragged_tab_controller.cc
index 38ab339..df1cd2b 100644
--- a/chrome/browser/views/tabs/dragged_tab_controller.cc
+++ b/chrome/browser/views/tabs/dragged_tab_controller.cc
@@ -108,6 +108,9 @@ DraggedTabController::~DraggedTabController() {
   // bounds, it won't be able to clean up properly since its cleanup routine
   // uses GetIndexForDraggedContents, which will be invalid.
   view_.reset(NULL);
+  // Make sure the TabContents doesn't think we're still its delegate.
+  if (dragged_contents_ && dragged_contents_->delegate() == this)
+    dragged_contents_->set_delegate(NULL);
   ChangeDraggedContents(NULL); // This removes our observer.
 }
 
@@ -290,17 +293,15 @@ gfx::Point DraggedTabController::GetWindowCreatePoint() const {
 
 void DraggedTabController::ChangeDraggedContents(TabContents* new_contents) {
   if (dragged_contents_) {
-    dragged_contents_->set_delegate(NULL);
     NotificationService::current()->RemoveObserver(this,
-      NOTIFY_TAB_CONTENTS_DESTROYED,
-      Source<TabContents>(dragged_contents_));
+        NOTIFY_TAB_CONTENTS_DESTROYED,
+        Source<TabContents>(dragged_contents_));
   }
   dragged_contents_ = new_contents;
   if (dragged_contents_) {
-    dragged_contents_->set_delegate(this);
     NotificationService::current()->AddObserver(this,
-      NOTIFY_TAB_CONTENTS_DESTROYED,
-      Source<TabContents>(dragged_contents_));
+        NOTIFY_TAB_CONTENTS_DESTROYED,
+        Source<TabContents>(dragged_contents_));
   }
 }
 
diff --git a/chrome/views/custom_frame_window.cc b/chrome/views/custom_frame_window.cc
index 3221e76..33df287 100644
--- a/chrome/views/custom_frame_window.cc
+++ b/chrome/views/custom_frame_window.cc
@@ -886,7 +886,8 @@ class NonClientViewLayout : public LayoutManager {
 CustomFrameWindow::CustomFrameWindow(WindowDelegate* window_delegate)
     : Window(window_delegate),
       is_active_(false),
-      lock_updates_(false) {
+      lock_updates_(false),
+      saved_window_style_(0) {
   InitClass();
   non_client_view_ = new DefaultNonClientView(this);
 }
@@ -1339,13 +1340,12 @@ void CustomFrameWindow::InitClass() {
 
 void CustomFrameWindow::LockUpdates() {
   lock_updates_ = true;
-  // This message causes invalidations to be discarded until it is called again
-  // with WPARAM TRUE (see UnlockUpdates).
-  SendMessage(GetHWND(), WM_SETREDRAW, FALSE, 0);
+  saved_window_style_ = GetWindowLong(GetHWND(), GWL_STYLE);
+  SetWindowLong(GetHWND(), GWL_STYLE, saved_window_style_ & ~WS_VISIBLE);
 }
 
 void CustomFrameWindow::UnlockUpdates() {
-  SendMessage(GetHWND(), WM_SETREDRAW, TRUE, 0);
+  SetWindowLong(GetHWND(), GWL_STYLE, saved_window_style_);
   lock_updates_ = false;
 }
 
diff --git a/chrome/views/custom_frame_window.h b/chrome/views/custom_frame_window.h
index 0c2b7f9..85c6b2d 100644
--- a/chrome/views/custom_frame_window.h
+++ b/chrome/views/custom_frame_window.h
@@ -89,6 +89,9 @@ class CustomFrameWindow : public Window {
   // True if updates to this window are currently locked.
   bool lock_updates_;
 
+  // The window styles of the window before updates were locked.
+  DWORD saved_window_style_;
+
   // Static resource initialization.
   static void InitClass();
   enum ResizeCursor {