Added device count test.

Added device count test.

BUG=313173

[Dmitry Zvorygin, 2014-05-12 14:39:09]

Please take a look.

[Vladislav Kaznacheev, 2014-05-12 17:21:08]

https://codereview.chromium.org/278343002/diff/1/chrome/browser/devtools/devi...
File chrome/browser/devtools/device/usb/android_usb_browser_test.cc (right):

https://codereview.chromium.org/278343002/diff/1/chrome/browser/devtools/devi...
chrome/browser/devtools/device/usb/android_usb_browser_test.cc:222:
adb_bridge_->set_polling_interval_for_test(1);
You can do without this call if you just remove and re-add the listener every
time you want to restart polling.

[Dmitry Zvorygin, 2014-05-15 11:35:13]

https://codereview.chromium.org/278343002/diff/1/chrome/browser/devtools/devi...
File chrome/browser/devtools/device/usb/android_usb_browser_test.cc (right):

https://codereview.chromium.org/278343002/diff/1/chrome/browser/devtools/devi...
chrome/browser/devtools/device/usb/android_usb_browser_test.cc:222:
adb_bridge_->set_polling_interval_for_test(1);
On 2014/05/12 17:21:08, Vladislav Kaznacheev wrote:
> You can do without this call if you just remove and re-add the listener every
> time you want to restart polling.

Done.

[Vladislav Kaznacheev, 2014-05-19 08:27:23]

https://codereview.chromium.org/278343002/diff/60001/chrome/browser/devtools/...
File chrome/browser/devtools/device/usb/android_usb_browser_test.cc (right):

https://codereview.chromium.org/278343002/diff/60001/chrome/browser/devtools/...
chrome/browser/devtools/device/usb/android_usb_browser_test.cc:156:
STLClearObject(devices);
Which thread is this called on? I see devices_ modified from UI thread in line
207 and below.

https://codereview.chromium.org/278343002/diff/60001/chrome/browser/devtools/...
chrome/browser/devtools/device/usb/android_usb_browser_test.cc:180: runner_ =
new content::MessageLoopRunner;
runner_ is initialized here but adb_bridge_ is initialized in the test body. Is
there a reason for this? I would rather move adb_bridge initialization and
AddListener call here.

[Dmitry Zvorygin, 2014-05-19 13:42:02]

Please take a look.

https://codereview.chromium.org/278343002/diff/60001/chrome/browser/devtools/...
File chrome/browser/devtools/device/usb/android_usb_browser_test.cc (right):

https://codereview.chromium.org/278343002/diff/60001/chrome/browser/devtools/...
chrome/browser/devtools/device/usb/android_usb_browser_test.cc:156:
STLClearObject(devices);
On 2014/05/19 08:27:23, Vladislav Kaznacheev wrote:
> Which thread is this called on? I see devices_ modified from UI thread in line
> 207 and below.

Done.

https://codereview.chromium.org/278343002/diff/60001/chrome/browser/devtools/...
chrome/browser/devtools/device/usb/android_usb_browser_test.cc:180: runner_ =
new content::MessageLoopRunner;
On 2014/05/19 08:27:23, Vladislav Kaznacheev wrote:
> runner_ is initialized here but adb_bridge_ is initialized in the test body.
Is
> there a reason for this? I would rather move adb_bridge initialization and
> AddListener call here.

Done.

[Vladislav Kaznacheev, 2014-05-19 18:07:13]

https://codereview.chromium.org/278343002/diff/80001/chrome/browser/devtools/...
File chrome/browser/devtools/device/usb/android_usb_browser_test.cc (right):

https://codereview.chromium.org/278343002/diff/80001/chrome/browser/devtools/...
chrome/browser/devtools/device/usb/android_usb_browser_test.cc:158: //
AndroidUsbBrowserTest::DeviceCountChanged.
This looks too fragile. If someone changes the way UsbService is assessed this
test will break and that poor someone will have to guess how they deserved it.

[Dmitry Zvorygin, 2014-05-20 09:14:36]

https://codereview.chromium.org/278343002/diff/80001/chrome/browser/devtools/...
File chrome/browser/devtools/device/usb/android_usb_browser_test.cc (right):

https://codereview.chromium.org/278343002/diff/80001/chrome/browser/devtools/...
chrome/browser/devtools/device/usb/android_usb_browser_test.cc:158: //
AndroidUsbBrowserTest::DeviceCountChanged.
On 2014/05/19 18:07:14, Vladislav Kaznacheev wrote:
> This looks too fragile. If someone changes the way UsbService is assessed this
> test will break and that poor someone will have to guess how they deserved it.

I don't think that some day there would be no "GetDevices" method to enumerate
devices.

Is somebody would remove this method, then, surely he would have to rewrite
device enumeration code in DevtoolsAndroidBridge, and rewrite this test
accordingly.

Don't see huge problem here.

[Vladislav Kaznacheev, 2014-05-20 13:15:36]

lgtm

[Dmitry Zvorygin, 2014-05-20 18:34:48]

The CQ bit was checked by zvorygin@chromium.org

[Dmitry Zvorygin, 2014-05-20 18:35:03]

The CQ bit was unchecked by zvorygin@chromium.org