Increased battery time to empty sent by power manager stub impl

chrome/browser/chromeos/dbus/power_manager_client.cc

 // Copyright (c) 2011 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 "chrome/browser/chromeos/dbus/power_manager_client.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/format_macros.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 293 matching lines @@
         pause_count_ = 20;
         return;
       }
     }
     battery_percentage_ += (discharging_ ? -1 : 1);
 
     PowerSupplyStatus status;
     status.line_power_on = !discharging_;
     status.battery_is_present = true;
     status.battery_percentage = battery_percentage_;
+    // We don't want to go to low because we don't want a low battery
+    // notification to pop up.
     status.battery_seconds_to_empty =
-        std::max(1, battery_percentage_ * 180 / 100);
+        std::max(16, battery_percentage_ * 180 / 100);

[satorux1, 2011/11/14 22:03:05]

Why did we end up showing the low battery balloon in browser_tests from the
beginning?

Looking at the code, the battery percentage started from 80%, and decreases by 1
point every time Update() is called.

Update() is called by a repeating timer every 100 ms from the first time
RequestStatusUpdate() is called. Hence it only needed 8 seconds to drain the
battery.

I'd say 100ms is too aggressive. We could make it something like 5 seconds for
now.

Besides, the magic number 180 looks cryptic. This is the number of  seconds to
fully charge the battery, right? 180 looks unrealistically short. I think we
should define a constant with a more realistic number, like

kNumSecondsToFullyChargeBattery = 60 * 120;  // 120 mins.

[satorux1, 2011/11/14 22:10:41]

FWIW, it used to be 3 hours, but changed to 180 seconds in this patch:

http://codereview.chromium.org/8347016/diff/27003/chrome/browser/chromeos/cro...

Which is partly my fault as I wasn't able to catch the undesirable change.

     status.battery_seconds_to_full =
         std::max(static_cast<int64>(1), 180 - status.battery_seconds_to_empty);
 
     FOR_EACH_OBSERVER(Observer, observers_, PowerChanged(status));
   }
 
   bool discharging_;
   int battery_percentage_;
   int pause_count_;
   ObserverList<Observer> observers_;
   base::RepeatingTimer<PowerManagerClientStubImpl> timer_;
 };
 
 PowerManagerClient::PowerManagerClient() {
 }
 
 PowerManagerClient::~PowerManagerClient() {
 }
 
 PowerManagerClient* PowerManagerClient::Create(dbus::Bus* bus) {
   if (system::runtime_environment::IsRunningOnChromeOS()) {
     return new PowerManagerClientImpl(bus);
   } else {
     return new PowerManagerClientStubImpl();
   }
 }
 
 }  // namespace chromeos