Create a base agent class for ui_devtools

Create a base agent class for ui_devtools

Each ui component such as ash, must create its own agents that implement
various backends (such as DOM or CSS). Each agent must be wired to the
main dispatcher so that it can receive events. In addition, each agent
must have access to a FrontendChannel instance so that it can push
updates to the inspector. This change creates a base agent which
abstracts out all of this. Any agent, like a DOM or CSS agent simply
inherit from this class and whenever they are attached to the
UiDevToolsClient, they are then initialized. This means they are
wired up and the FrontendChannel instance is set with the dispatcher
available from UiDevToolsClient.

This is what DevTools does for their agents, and this CL implements
a simpler version of that.

BUG=648701
Committed: https://crrev.com/e2445fe73810b097225b9ed1caedafe0251a2120
Cr-Commit-Position: refs/heads/master@{#428615}

[Sarmad Hashmi, 2016-10-26 20:47:34]

mhashmi@chromium.org changed reviewers:
+ sadrul@chromium.org

[Sarmad Hashmi, 2016-10-26 20:47:34]

This CL will allow backends to be added and initialized in a more generic way as
opposed to AddDOMBackend or AddCSSBackend. And, each backend will have a
corresponding frontend instance so we can push updates (i.e: when a window is
destroyed).

[Sarmad Hashmi, 2016-10-26 20:56:18]

The CQ bit was checked by mhashmi@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-10-26 20:56:53]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-26 21:09:39]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-10-26 21:09:40]

Dry run: This issue passed the CQ dry run.

[sadrul, 2016-10-28 02:06:15]

sadrul@chromium.org changed reviewers:
+ dgozman@chromium.org

[sadrul, 2016-10-28 02:06:16]

looks good to me. +dgozman@ for devtools owner review.

https://codereview.chromium.org/2456643002/diff/40001/components/ui_devtools/...
File components/ui_devtools/devtools_base_agent.h (right):

https://codereview.chromium.org/2456643002/diff/40001/components/ui_devtools/...
components/ui_devtools/devtools_base_agent.h:6: #define
COMPONENTS_UI_DEVTOOLS_DEVTOOLS_BASE_AGENT_H_
Add this file in BUILD.gn as well?

https://codereview.chromium.org/2456643002/diff/40001/components/ui_devtools/...
components/ui_devtools/devtools_base_agent.h:43: std::unique_ptr<typename
DomainMetainfo::FrontendClass> m_frontend;
frontend_

[dgozman, 2016-10-28 02:11:54]

lgtm

[Sarmad Hashmi, 2016-10-28 18:52:01]

https://codereview.chromium.org/2456643002/diff/40001/components/ui_devtools/...
File components/ui_devtools/devtools_base_agent.h (right):

https://codereview.chromium.org/2456643002/diff/40001/components/ui_devtools/...
components/ui_devtools/devtools_base_agent.h:6: #define
COMPONENTS_UI_DEVTOOLS_DEVTOOLS_BASE_AGENT_H_
On 2016/10/28 02:06:16, sadrul wrote:
> Add this file in BUILD.gn as well?

Done.

https://codereview.chromium.org/2456643002/diff/40001/components/ui_devtools/...
components/ui_devtools/devtools_base_agent.h:43: std::unique_ptr<typename
DomainMetainfo::FrontendClass> m_frontend;
On 2016/10/28 02:06:16, sadrul wrote:
> frontend_

Done.

[sadrul, 2016-10-29 05:49:15]

lgtm with the nits addressed.

https://codereview.chromium.org/2456643002/diff/60001/components/ui_devtools/...
File components/ui_devtools/devtools_base_agent.h (right):

https://codereview.chromium.org/2456643002/diff/60001/components/ui_devtools/...
components/ui_devtools/devtools_base_agent.h:18: virtual void
init(protocol::UberDispatcher*) = 0;
Init. (Should've caught this in the first iteration, sorry)

https://codereview.chromium.org/2456643002/diff/60001/components/ui_devtools/...
components/ui_devtools/devtools_base_agent.h:30: void
init(protocol::UberDispatcher* dispatcher) {
Init

[Sarmad Hashmi, 2016-10-29 16:11:09]

https://codereview.chromium.org/2456643002/diff/60001/components/ui_devtools/...
File components/ui_devtools/devtools_base_agent.h (right):

https://codereview.chromium.org/2456643002/diff/60001/components/ui_devtools/...
components/ui_devtools/devtools_base_agent.h:18: virtual void
init(protocol::UberDispatcher*) = 0;
On 2016/10/29 05:49:15, sadrul wrote:
> Init. (Should've caught this in the first iteration, sorry)

Done.

https://codereview.chromium.org/2456643002/diff/60001/components/ui_devtools/...
components/ui_devtools/devtools_base_agent.h:30: void
init(protocol::UberDispatcher* dispatcher) {
On 2016/10/29 05:49:15, sadrul wrote:
> Init

Done.

[Sarmad Hashmi, 2016-10-29 16:11:14]

The CQ bit was checked by mhashmi@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-10-29 16:11:22]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-29 17:00:54]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-10-29 17:00:55]

Dry run: This issue passed the CQ dry run.

[Sarmad Hashmi, 2016-10-29 20:41:06]

The CQ bit was checked by mhashmi@chromium.org

[Sarmad Hashmi, 2016-10-29 20:41:06]

The patchset sent to the CQ was uploaded after l-g-t-m from
dgozman@chromium.org, sadrul@chromium.org
Link to the patchset: https://codereview.chromium.org/2456643002/#ps80001
(title: "sadruls comments")

[commit-bot: I haz the power, 2016-10-29 20:41:13]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-29 20:47:38]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2016-10-29 20:50:55]

Description was changed from

==========
Create a base agent class for ui_devtools

Each ui component such as ash, must create its own agents that implement
various backends (such as DOM or CSS). Each agent must be wired to the
main dispatcher so that it can receive events. In addition, each agent
must have access to a FrontendChannel instance so that it can push
updates to the inspector. This change creates a base agent which
abstracts out all of this. Any agent, like a DOM or CSS agent simply
inherit from this class and whenever they are attached to the
UiDevToolsClient, they are then initialized. This means they are
wired up and the FrontendChannel instance is set with the dispatcher
available from UiDevToolsClient.

This is what DevTools does for their agents, and this CL implements
a simpler version of that.

BUG=648701
==========

to

==========
Create a base agent class for ui_devtools

Each ui component such as ash, must create its own agents that implement
various backends (such as DOM or CSS). Each agent must be wired to the
main dispatcher so that it can receive events. In addition, each agent
must have access to a FrontendChannel instance so that it can push
updates to the inspector. This change creates a base agent which
abstracts out all of this. Any agent, like a DOM or CSS agent simply
inherit from this class and whenever they are attached to the
UiDevToolsClient, they are then initialized. This means they are
wired up and the FrontendChannel instance is set with the dispatcher
available from UiDevToolsClient.

This is what DevTools does for their agents, and this CL implements
a simpler version of that.

BUG=648701

Committed: https://crrev.com/e2445fe73810b097225b9ed1caedafe0251a2120
Cr-Commit-Position: refs/heads/master@{#428615}
==========

[commit-bot: I haz the power, 2016-10-29 20:50:56]

Patchset 5 (id:??) landed as
https://crrev.com/e2445fe73810b097225b9ed1caedafe0251a2120
Cr-Commit-Position: refs/heads/master@{#428615}