Fix large mis-paint when resizing windows aura chrome

ui/compositor/compositor.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/compositor/compositor.h"
 
 #include <algorithm>
 #include <deque>
 
 #include "base/bind.h"
@@ skipping 393 matching lines @@
 Compositor::Compositor(CompositorDelegate* delegate,
                        gfx::AcceleratedWidget widget)
     : delegate_(delegate),
       root_layer_(NULL),
       widget_(widget),
       posted_swaps_(new PostedSwapQueue()),
       device_scale_factor_(0.0f),
       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));
 
   CommandLine* command_line = CommandLine::ForCurrentProcess();
 
   cc::LayerTreeSettings settings;
   settings.refresh_rate =
       g_test_compositor_enabled ? kTestRefreshRate : kDefaultRefreshRate;
   settings.partial_swap_enabled =
@@ skipping 96 matching lines @@
   if (!root_layer_)
     return;
 
   last_started_frame_++;
   PendingSwap pending_swap(DRAW_SWAP, posted_swaps_.get());
   if (!IsLocked()) {
     // TODO(nduca): Temporary while compositor calls
     // 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();
 }
 
 void Compositor::ScheduleFullDraw() {
   host_->SetNeedsRedraw();
 }
 
 bool Compositor::ReadPixels(SkBitmap* bitmap,
@@ skipping 10 matching lines @@
   PendingSwap pending_swap(READPIXELS_SWAP, posted_swaps_.get());
   return host_->CompositeAndReadback(pixels, bounds_in_pixel);
 }
 
 void Compositor::SetScaleAndSize(float scale, const gfx::Size& size_in_pixel) {
   DCHECK_GT(scale, 0);
   if (!size_in_pixel.IsEmpty()) {
     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;
     if (root_layer_)
       root_layer_->OnDeviceScaleFactorChanged(scale);
   }
 }
 
 void Compositor::SetBackgroundColor(SkColor color) {
   host_->set_background_color(color);
@@ skipping 159 matching lines @@
 COMPOSITOR_EXPORT void DisableTestCompositor() {
   ResetImplicitFactory();
   g_test_compositor_enabled = false;
 }
 
 COMPOSITOR_EXPORT bool IsTestCompositorEnabled() {
   return g_test_compositor_enabled;
 }
 
 }  // namespace ui