Fix large mis-paint when resizing windows aura chrome

ui/compositor/compositor.cc

Index: ui/compositor/compositor.cc
===================================================================
--- ui/compositor/compositor.cc	(revision 192187)
+++ ui/compositor/compositor.cc	(working copy)
@@ -411,6 +411,7 @@
       last_started_frame_(0),
       last_ended_frame_(0),
       disable_schedule_composite_(false),
+      is_resizing_ (false),

[piman, 2013/04/04 21:56:14]

nit: would next_draw_is_resize_ be a better name?

[cpu_(ooo_6.6-7.5), 2013/04/05 17:05:51]

If you really want it, sure, the current name describes the state which and the
proposed name describes the intent of the fix, I like #1 but not too attached.

[piman, 2013/04/05 17:15:32]

well, imo, "is_resizing_" suggests that it's a state that'd stay true while
you're dragging the window border, whereas in reality it's only true from the
point we call SetScaleAndSize to the point where we draw at that size, hence
encoding in the name that this state is only meaningful until the next draw.

       compositor_lock_(NULL) {
   root_web_layer_ = cc::Layer::Create();
   root_web_layer_->SetAnchorPoint(gfx::PointF(0.f, 0.f));
@@ -527,6 +528,18 @@
     // compositeImmediately() directly.
     Layout();
     host_->Composite(base::TimeTicks::Now());
+
+#if defined(OS_WIN)
+    // While we resize, we are usually a few frames behind. By blocking
+    // the UI thread here we minize the area that is mis-painted, specially
+    // in the non-client area. See RenderWidgetHostViewAura::SetBounds for
+    // more details and bug 177115.
+    if (is_resizing_ && (last_ended_frame_ > 1)) {

[piman, 2013/04/04 21:56:14]

nit: >1 or >0?
We only want to not wait on the first frame, right?

[cpu_(ooo_6.6-7.5), 2013/04/05 17:05:51]

I see two passing by, one is pure white and the second one has bits.

+      is_resizing_ = false;
+      host_->FinishAllRendering();
+    }
+#endif
+
   }
   if (!pending_swap.posted())
     NotifyEnd();
@@ -557,6 +570,8 @@
     size_ = size_in_pixel;
     host_->SetViewportSize(size_in_pixel, size_in_pixel);
     root_web_layer_->SetBounds(size_in_pixel);
+
+    is_resizing_ = true;
   }
   if (device_scale_factor_ != scale) {
     device_scale_factor_ = scale;