Create DevToolsHttp and basic DevToolsClientBackend.

Create DevToolsHttp and basic DevToolsClientBackend.
Use new nomenclature (DevTools instead of Inspector), to match rest of Chromium.

BUG=423954, 443897
Committed: https://crrev.com/6be74066498a1cfb66e5d5d19a81dc1f9a50e799
Cr-Commit-Position: refs/heads/master@{#309331}

[chrishenry, 2014-12-19 22:32:15]

Patchset #1 (id:1) has been deleted

[chrishenry, 2014-12-19 22:42:23]

chrishenry@google.com changed reviewers:
+ ariblue@google.com, dtu@chromium.org, nednguyen@google.com, tonyg@chromium.org

[chrishenry, 2014-12-19 22:42:24]

I split this, hopefully less controversial, part from
https://codereview.chromium.org/813283002/

This patch only introduced DevToolsHttp and DevToolsClientBackend supporting a
few devtools command. The code gets a tad simpler, which is nice, except for
some exception handling in chrome_browser_backend... Ideas welcome!

[chrishenry, 2014-12-19 22:42:37]

Patchset #1 (id:20001) has been deleted

[tonyg, 2014-12-20 01:33:55]

Looks reasonable to me. A few nits/questions.

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py
(left):

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py:170:
exceptions.BrowserConnectionGoneException):
In the new code, I didn't see these exceptions being caught. Can you explain
why?

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/core/backends/chrome/tracing_backend.py (right):

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
tools/telemetry/telemetry/core/backends/chrome/tracing_backend.py:52:
#TODO(nednguyen): remove this when the stable branch pass 2118.
Stable is 2171 now so you can just remove this whole block rather than updating
it.

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/core/browser_unittest.py (right):

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
tools/telemetry/telemetry/core/browser_unittest.py:34: self.assertTrue(v > 0)
While you're here, this should really use assertGreater(). Also, the suppressed
lint warning is about accessing _browser_backend here. I wonder whether we could
move this test case into one of your new files now.

[chrishenry, 2014-12-20 01:49:24]

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py
(left):

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py:170:
exceptions.BrowserConnectionGoneException):
On 2014/12/20 01:33:55, tonyg (OOO til Jan 5) wrote:
> In the new code, I didn't see these exceptions being caught. Can you explain
> why?

This exception is a wrapper over the original network exception. In the new
code, we catch a different wrapper (over the same network exception) in
IsAlive() call.

Think of it as: IsAlive() makes a Request() to devtools server, if it encounters
any network error, it returns false. This is equivalent to the old definition of
HasBrowserFinishedLaunching()

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/core/backends/chrome/tracing_backend.py (right):

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
tools/telemetry/telemetry/core/backends/chrome/tracing_backend.py:52:
#TODO(nednguyen): remove this when the stable branch pass 2118.
On 2014/12/20 01:33:55, tonyg (OOO til Jan 5) wrote:
> Stable is 2171 now so you can just remove this whole block rather than
updating
> it.

I wasn't sure about WebView. Do you know what's the branch number of L WebView?
(In fact, now that I think about it, does it even have a branch number?)

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/core/browser_unittest.py (right):

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
tools/telemetry/telemetry/core/browser_unittest.py:34: self.assertTrue(v > 0)
On 2014/12/20 01:33:55, tonyg (OOO til Jan 5) wrote:
> While you're here, this should really use assertGreater(). Also, the
suppressed
> lint warning is about accessing _browser_backend here. I wonder whether we
could
> move this test case into one of your new files now.

Yeah, actually yes. I wasn't reading the test... ): This is now tested by the
new logic.

[tonyg, 2014-12-20 02:01:05]

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py
(left):

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py:170:
exceptions.BrowserConnectionGoneException):
On 2014/12/20 01:49:24, chrishenry (OOO until Jan 5) wrote:
> On 2014/12/20 01:33:55, tonyg (OOO til Jan 5) wrote:
> > In the new code, I didn't see these exceptions being caught. Can you explain
> > why?
> 
> This exception is a wrapper over the original network exception. In the new
> code, we catch a different wrapper (over the same network exception) in
> IsAlive() call.
> 
> Think of it as: IsAlive() makes a Request() to devtools server, if it
encounters
> any network error, it returns false. This is equivalent to the old definition
of
> HasBrowserFinishedLaunching()

If that's true for BrowserGoneException as well, then this lgtm.

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/core/backends/chrome/tracing_backend.py (right):

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
tools/telemetry/telemetry/core/backends/chrome/tracing_backend.py:52:
#TODO(nednguyen): remove this when the stable branch pass 2118.
On 2014/12/20 01:49:24, chrishenry (OOO until Jan 5) wrote:
> On 2014/12/20 01:33:55, tonyg (OOO til Jan 5) wrote:
> > Stable is 2171 now so you can just remove this whole block rather than
> updating
> > it.
> 
> I wasn't sure about WebView. Do you know what's the branch number of L
WebView?
> (In fact, now that I think about it, does it even have a branch number?)

Good catch. The stock webview is back on M37 (although it is updatable now).

[chrishenry, 2014-12-20 02:12:07]

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py
(left):

https://codereview.chromium.org/811263005/diff/60001/tools/telemetry/telemetr...
tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py:170:
exceptions.BrowserConnectionGoneException):
On 2014/12/20 02:01:05, tonyg (OOO til Jan 5) wrote:
> On 2014/12/20 01:49:24, chrishenry (OOO until Jan 5) wrote:
> > On 2014/12/20 01:33:55, tonyg (OOO til Jan 5) wrote:
> > > In the new code, I didn't see these exceptions being caught. Can you
explain
> > > why?
> > 
> > This exception is a wrapper over the original network exception. In the new
> > code, we catch a different wrapper (over the same network exception) in
> > IsAlive() call.
> > 
> > Think of it as: IsAlive() makes a Request() to devtools server, if it
> encounters
> > any network error, it returns false. This is equivalent to the old
definition
> of
> > HasBrowserFinishedLaunching()
> 
> If that's true for BrowserGoneException as well, then this lgtm.

This is true for BGE as well.

[chrishenry, 2014-12-20 02:55:32]

The CQ bit was checked by chrishenry@google.com

[commit-bot: I haz the power, 2014-12-20 02:56:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/811263005/80001

[commit-bot: I haz the power, 2014-12-20 03:39:15]

Committed patchset #3 (id:80001)

[commit-bot: I haz the power, 2014-12-20 03:40:09]

Patchset 3 (id:??) landed as
https://crrev.com/6be74066498a1cfb66e5d5d19a81dc1f9a50e799
Cr-Commit-Position: refs/heads/master@{#309331}