Change behavior of a couple truncating divisions to rounding.

Both of these locations are approximating a higher-precision number
with a lower one for human consumption, so rounding produces the least
error.  (In practice the difference won't be noticed; the more desirable
effect of this change is to use explicit safe float->int conversions.)

Bug: 1104532
Change-Id: I2173e7848778c99f9eb629870bc0c5383d5cb263
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2293630
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Ahmed Fakhry <afakhry@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#787932}

ash/app_list/views/expand_arrow_view.cc

@@ -4,6 +4,7 @@
 
 #include "ash/app_list/views/expand_arrow_view.h"
 
+#include <algorithm>
 #include <memory>
 #include <utility>
 
@@ -14,6 +15,7 @@
 #include "ash/public/cpp/app_list/vector_icons/vector_icons.h"
 #include "base/bind.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/numerics/safe_conversions.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/animation/slide_animation.h"
 #include "ui/gfx/canvas.h"
@@ -333,7 +335,7 @@ void ExpandArrowView::AnimationProgressed(const gfx::Animation* animation) {
   }
 
   // Update pulse radius.
-  pulse_radius_ = static_cast<int>(
+  pulse_radius_ = base::Round(
       (kPulseMaxRadius - kPulseMinRadius) *
       gfx::Tween::CalculateValue(
           gfx::Tween::EASE_IN_OUT,
@@ -349,14 +351,14 @@ void ExpandArrowView::AnimationProgressed(const gfx::Animation* animation) {
     const double progress =
         (time - kArrowMoveOutBeginTime).InMillisecondsF() /
         (kArrowMoveOutEndTime - kArrowMoveOutBeginTime).InMillisecondsF();
-    arrow_y_offset_ = static_cast<int>(
-        -kTotalArrowYOffset *
+    arrow_y_offset_ =
+        base::Round(-kTotalArrowYOffset *
                     gfx::Tween::CalculateValue(gfx::Tween::EASE_IN, progress));
   } else if (time > kArrowMoveInBeginTime && time <= kArrowMoveInEndTime) {
     const double progress =
         (time - kArrowMoveInBeginTime).InMillisecondsF() /
         (kArrowMoveInEndTime - kArrowMoveInBeginTime).InMillisecondsF();
-    arrow_y_offset_ = static_cast<int>(
+    arrow_y_offset_ = base::Round(
         kTotalArrowYOffset *
         (1 - gfx::Tween::CalculateValue(gfx::Tween::EASE_OUT, progress)));
   }

chrome/browser/task_manager/providers/task.cc

@@ -6,6 +6,7 @@
 
 #include <stddef.h>
 
+#include "base/numerics/safe_conversions.h"
 #include "base/process/process.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
@@ -92,15 +93,13 @@ void Task::Refresh(const base::TimeDelta& update_interval,
 
   int64_t current_cycle_read_byte_count =
       cumulative_bytes_read_ - last_refresh_cumulative_bytes_read_;
-  network_read_rate_ =
-      (current_cycle_read_byte_count * base::TimeDelta::FromSeconds(1)) /
-      update_interval;
+  network_read_rate_ = base::Round<int64_t>(current_cycle_read_byte_count /
+                                            update_interval.InSecondsF());
 
   int64_t current_cycle_sent_byte_count =
       cumulative_bytes_sent_ - last_refresh_cumulative_bytes_sent_;
-  network_sent_rate_ =
-      (current_cycle_sent_byte_count * base::TimeDelta::FromSeconds(1)) /
-      update_interval;
+  network_sent_rate_ = base::Round<int64_t>(current_cycle_sent_byte_count /
+                                            update_interval.InSecondsF());
 
   last_refresh_cumulative_bytes_read_ = cumulative_bytes_read_;
   last_refresh_cumulative_bytes_sent_ = cumulative_bytes_sent_;