[Ozone DRM] Don't round refresh rate for PresentationFeedback.

HardwareDisplayController::GetRefreshInterval() was using the integer
rounded refresh rate instead of a float value. The rounded refresh was
used to construct PresentationFeedback, which ultimately gets used to
set the begin frame and exo vsync interval. On veyron_minnie this
changed the interval from 16819us to 16666us incorrectly.

Bug: 907625
Change-Id: I0e7a2a776cdadfa0bb99b67735ab93beb90a0f63
Reviewed-on: https://chromium-review.googlesource.com/c/1347444Reviewed-by: Michael Spang <spang@chromium.org>
Commit-Queue: kylechar <kylechar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610227}

ui/ozone/platform/drm/gpu/hardware_display_controller.cc

@@ -309,13 +309,9 @@ gfx::Size HardwareDisplayController::GetModeSize() const {
                    crtc_controllers_[0]->mode().vdisplay);
 }
 
-uint32_t HardwareDisplayController::GetRefreshRate() const {
-  // If there are multiple CRTCs they should all have the same size.
-  return crtc_controllers_[0]->mode().vrefresh;
-}
-
 base::TimeDelta HardwareDisplayController::GetRefreshInterval() const {
-  uint32_t vrefresh = GetRefreshRate();
+  // If there are multiple CRTCs they should all have the same refresh rate.
+  float vrefresh = ModeRefreshRate(crtc_controllers_[0]->mode());
   return vrefresh ? base::TimeDelta::FromSeconds(1) / vrefresh
                   : base::TimeDelta();
 }

ui/ozone/platform/drm/gpu/hardware_display_controller.h

@@ -156,7 +156,6 @@ class HardwareDisplayController {
   gfx::Point origin() const { return origin_; }
   void set_origin(const gfx::Point& origin) { origin_ = origin; }
 
-  uint32_t GetRefreshRate() const;
   base::TimeDelta GetRefreshInterval() const;
   base::TimeTicks GetTimeOfLastFlip() const;