Consolidate sensor fetch interval constant and increase fetch frequency to 20Hz.

Increase the sensor fetch frequency for all platforms for which
we have fetcher implementations (i.e. Android, Mac, Win) to a
max of 20Hz. This will provide more up-to-date sensor data to
Chrome and Blink and increase Device Orientation/Motion
responsiveness.

This patch includes the following:
- refactoring of data_fetcher_shared_memory_base to allow
  setting a default fetch interval and the possibility to
  override it per platform.
- consolidation of the default fetch interval constant in
  one place, i.e. inertial_sensor_consts.h.
- diagnostic html test webpage for testing average JavaScript
  Device Motion/Orientation event firing frequency.

BUG=261165
TEST=content/test/data/device_orientation/device_inertial_sensor_diagnostics.html (manual)
also available at: http://jsbin.com/device-inertial-sensor-diagnostics/latest

Review URL: https://codereview.chromium.org/23601040

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229929 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229929
Improve prerender handling of NavigateParams.

There aren't many uses of extra_headers and use_post, but we shouldn't trigger
prerenders in those cases. Also update params->target_contents after swap and
follow through with chrome::Navigate cleanup code, as SwapInInstantNTP does.
Modify tests to assert the correct WebContents was returned out of
Browser::OpenURL.

BUG=none
TEST=PrerenderBrowserTest.PrerenderExtraHeadersNoSwap
     PrerenderBrowserTest.PrerenderBrowserInitiatedPostNoSwap

Review URL: https://codereview.chromium.org/26829003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229930 0039d316-1c4b-4281-b951-d872f2087c98
Relands Android perf tests: kill adbd on the device after running a test.

Third retry on crrev.com/226762.
Adds "wait-for-device".
There's some data indicating that adbd on the device sometimes
spontaneously restores its connection.
After running a test, let's kill adbd and wait for bit.

This is a speculative change to try to make the bots healthier.

BUG=268450

Review URL: https://codereview.chromium.org/32163002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229931 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229931