Scale bounds in DesktopWindowTreeHostMus and in calls to SetBounds.

blimp/client/app/linux/blimp_display_manager.cc

Index: blimp/client/app/linux/blimp_display_manager.cc
diff --git a/blimp/client/app/linux/blimp_display_manager.cc b/blimp/client/app/linux/blimp_display_manager.cc
index 1f1f10911bcec221aabb1ac6d3411f2b8e6b054f..28d877efbab17563f0c013a6091ef28f6a03698f 100644
--- a/blimp/client/app/linux/blimp_display_manager.cc
+++ b/blimp/client/app/linux/blimp_display_manager.cc
@@ -14,6 +14,7 @@
 #include "ui/events/gesture_detection/motion_event_generic.h"
 #include "ui/events/gestures/motion_event_aura.h"
 #include "ui/events/platform/platform_event_source.h"
+#include "ui/gfx/geometry/dip_util.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/platform_window/platform_window.h"
 #include "ui/platform_window/x11/x11_window.h"
@@ -40,7 +41,8 @@ BlimpDisplayManager::BlimpDisplayManager(
 BlimpDisplayManager::~BlimpDisplayManager() = default;
 
 void BlimpDisplayManager::SetWindowSize(const gfx::Size& window_size) {
-  platform_window_->SetBounds(gfx::Rect(window_size));
+  platform_window_->SetBounds(gfx::ConvertRectToPixel(1.f / device_pixel_ratio_,
+                                                      gfx::Rect(window_size)));

[sadrul, 2016/11/17 20:26:21]

Are you sure you want 1.f / device_pixel_ratio_?

[riajiang, 2016/11/17 21:43:28]

When device_pixel_ratio_ is used (e.g.
https://cs.chromium.org/chromium/src/blimp/client/app/linux/blimp_display_man...),
it is sent to a function with the comment that says this is "in terms of dp to
px" (I think the name also suggests this) - which is the opposite of what we are
using for device_scale_factor? 

[sadrul, 2016/11/18 01:23:55]

I am not really sure what you mean. But, PlatformWindow::SetBounds() expects
bounds in physical-pixels. If |window_size| is in DIP, then you need to convert
from DIP to physical pixel (i.e. scale up by device_pixel_ratio_). If
|window_size| is already in pixels, then you don't need to do any conversion at
all. You should confirm with a blimp owner what pixels |window_size| is in.

[riajiang, 2016/11/18 01:49:34]

Yes gfx::ConvertRectToPixel will convert window_size to pixel - it is expecting
device_scale_factor as the first param tho, which is pixel/dip, but
device_pixel_ratio_ is dip/pixel, that's why I used 1.f/device_pixel_ratio_. Did
I miss something? 
window_size is constant 800*600
(https://cs.chromium.org/chromium/src/blimp/client/app/linux/blimp_main.cc?sq=...),
so I thought it was in dip?

[riajiang, 2016/11/18 20:19:12]

As discussed with sadrul@ offline, |device_pixel_ratio_| should actually be
px/dip as well. Changed it to just use |device_pixel_ratio_| and updated the
comment about |device_pixel_ratio_|.

 }
 
 void BlimpDisplayManager::SetBlimpContents(