Fix a DCHECK that I hit while working on the extension shelf for OS X.

BUG=Part of 19073
TEST=unittest in CL

Review URL: http://codereview.chromium.org/185015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@25261 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 32 insertions, 0 deletions

diff --git a/chrome/browser/renderer_host/render_widget_host.cc b/chrome/browser/renderer_host/render_widget_host.cc
index 40fba47..e14b846 100644
--- a/chrome/browser/renderer_host/render_widget_host.cc
+++ b/chrome/browser/renderer_host/render_widget_host.cc
@@ -224,6 +224,9 @@ void RenderWidgetHost::WasResized() {
   if (new_size == current_size_)
     return;
 
+  if (in_flight_size_ != gfx::Size() && new_size == in_flight_size_)
+    return;
+
   // We don't expect to receive an ACK when the requested size is empty.
   if (!new_size.IsEmpty())
     resize_ack_pending_ = true;
@@ -231,6 +234,8 @@ void RenderWidgetHost::WasResized() {
   if (!Send(new ViewMsg_Resize(routing_id_, new_size,
                                GetRootWindowResizerRect())))
     resize_ack_pending_ = false;
+  else
+    in_flight_size_ = new_size;
 }
 
 void RenderWidgetHost::GotFocus() {
@@ -588,6 +593,7 @@ void RenderWidgetHost::OnMsgPaintRect(
   if (is_resize_ack) {
     DCHECK(resize_ack_pending_);
     resize_ack_pending_ = false;
+    in_flight_size_.SetSize(0, 0);
   }
 
   bool is_repaint_ack =
diff --git a/chrome/browser/renderer_host/render_widget_host.h b/chrome/browser/renderer_host/render_widget_host.h
index 242d56b..b06bce3 100644
--- a/chrome/browser/renderer_host/render_widget_host.h
+++ b/chrome/browser/renderer_host/render_widget_host.h
@@ -460,6 +460,13 @@ class RenderWidgetHost : public IPC::Channel::Listener,
   // The current size of the RenderWidget.
   gfx::Size current_size_;
 
+  // The size we last sent as requested size to the renderer. |current_size_|
+  // is only updated once the resize message has been ack'd. This on the other
+  // hand is updated when the resize message is sent. This is very similar to
+  // |resize_ack_pending_|, but the latter is not set if the new size has width
+  // or height zero, which is why we need this too.
+  gfx::Size in_flight_size_;
+
   // True if a mouse move event was sent to the render view and we are waiting
   // for a corresponding ViewHostMsg_HandleInputEvent_ACK message.
   bool mouse_move_pending_;
diff --git a/chrome/browser/renderer_host/render_widget_host_unittest.cc b/chrome/browser/renderer_host/render_widget_host_unittest.cc
index 1b05260..4f16e8d 100644
--- a/chrome/browser/renderer_host/render_widget_host_unittest.cc
+++ b/chrome/browser/renderer_host/render_widget_host_unittest.cc
@@ -239,6 +239,25 @@ TEST_F(RenderWidgetHostTest, Resize) {
   host_->WasResized();
   EXPECT_FALSE(host_->resize_ack_pending_);
   EXPECT_TRUE(process_->sink().GetUniqueMessageMatching(ViewMsg_Resize::ID));
+
+  // Send a rect that has no area but has either width or height set.
+  process_->sink().ClearMessages();
+  view_->set_bounds(gfx::Rect(0, 0, 0, 30));
+  host_->WasResized();
+  EXPECT_FALSE(host_->resize_ack_pending_);
+  EXPECT_TRUE(process_->sink().GetUniqueMessageMatching(ViewMsg_Resize::ID));
+
+  // Set the same size again. It should not be sent again.
+  process_->sink().ClearMessages();
+  host_->WasResized();
+  EXPECT_FALSE(host_->resize_ack_pending_);
+  EXPECT_FALSE(process_->sink().GetFirstMessageMatching(ViewMsg_Resize::ID));
+
+  // A different size should be sent again, however.
+  view_->set_bounds(gfx::Rect(0, 0, 0, 31));
+  host_->WasResized();
+  EXPECT_FALSE(host_->resize_ack_pending_);
+  EXPECT_TRUE(process_->sink().GetUniqueMessageMatching(ViewMsg_Resize::ID));
 }
 
 // Tests setting custom background