Add new pattern for creating downstream objects

Add new pattern for creating downstream objects

This change introduces a new pattern for instantiating objects of
classes that have have differing upstream/downstream implementations.
If a class's constructor requires no parameters (as is most frequently
the case in this scenario), it can be created with:

    ChromeApplication.createObject(MyType.class);

And registered with no additional change upstream, and only a small
implementation (that does not require creating additional methods)
downstream.  Without this change, one must register a new method both
upstream and downstream as well as cast an application context to a
ChromeApplication before calling that newly registered return
type-specifc method.

BUG=685383
Review-Url: https://codereview.chromium.org/2655463008
Cr-Commit-Position: refs/heads/master@{#446394}
Committed: https://chromium.googlesource.com/chromium/src/+/5b52d760b18cc7b955ee0bf35cdfe7239f9ba0c7

[cco3, 2017-01-25 22:23:37]

cco3@chromium.org changed reviewers:
+ mariakhomenko@chromium.org

[cco3, 2017-01-25 22:23:38]

Hi Maria, would you be able to take a look at this change?  I've also added you
to its downstream complement.

[cco3, 2017-01-25 22:38:01]

Description was changed from

==========
Add new pattern for creating downstream objects

This change introduces a new pattern for instantiating objects of
classes that have have differing upstream/downstream implementations.
If a class's constructor requires no parameters (as is most frequently
the case in this scenario), it can be created with:

    ChromeApplication.createObject(MyType.class);

And registered with no additional change upstream, and only a small
implementation (that does not require creating additional methods)
downstream.  Without this change, one must register a new method both
upstream and downstream as well as cast an application context to a
ChromeApplication before calling that newly registered return
type-specifc method.
==========

to

==========
Add new pattern for creating downstream objects

This change introduces a new pattern for instantiating objects of
classes that have have differing upstream/downstream implementations.
If a class's constructor requires no parameters (as is most frequently
the case in this scenario), it can be created with:

    ChromeApplication.createObject(MyType.class);

And registered with no additional change upstream, and only a small
implementation (that does not require creating additional methods)
downstream.  Without this change, one must register a new method both
upstream and downstream as well as cast an application context to a
ChromeApplication before calling that newly registered return
type-specifc method.

BUG=685383
==========

[Maria, 2017-01-26 00:46:02]

https://codereview.chromium.org/2655463008/diff/20001/chrome/android/java/src...
File chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
(right):

https://codereview.chromium.org/2655463008/diff/20001/chrome/android/java/src...
chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java:440:
throw new RuntimeException("Asked to create unexpected class.");
add the name of the class into the message

[cco3, 2017-01-26 01:00:02]

https://codereview.chromium.org/2655463008/diff/20001/chrome/android/java/src...
File chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
(right):

https://codereview.chromium.org/2655463008/diff/20001/chrome/android/java/src...
chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java:440:
throw new RuntimeException("Asked to create unexpected class.");
On 2017/01/26 00:46:02, Maria wrote:
> add the name of the class into the message

Done.

[Maria, 2017-01-26 02:23:25]

lgtm % small comments

https://codereview.chromium.org/2655463008/diff/40001/chrome/android/java/src...
File chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
(right):

https://codereview.chromium.org/2655463008/diff/40001/chrome/android/java/src...
chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java:432:
public static <T> T createObject(Class<T> klass) {
missing javadoc

https://codereview.chromium.org/2655463008/diff/40001/chrome/android/java/src...
chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java:440:
throw new RuntimeException("Asked to create unexpected class: " +
klass.getName());
Let's pass e as the second parameter into RuntimeException -- I think this will
give us the real stack trace

[cco3, 2017-01-26 18:06:58]

https://codereview.chromium.org/2655463008/diff/40001/chrome/android/java/src...
File chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
(right):

https://codereview.chromium.org/2655463008/diff/40001/chrome/android/java/src...
chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java:432:
public static <T> T createObject(Class<T> klass) {
On 2017/01/26 02:23:25, Maria wrote:
> missing javadoc

Done.

https://codereview.chromium.org/2655463008/diff/40001/chrome/android/java/src...
chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java:440:
throw new RuntimeException("Asked to create unexpected class: " +
klass.getName());
On 2017/01/26 02:23:25, Maria wrote:
> Let's pass e as the second parameter into RuntimeException -- I think this
will
> give us the real stack trace

Done.

[cco3, 2017-01-26 18:47:31]

The CQ bit was checked by cco3@chromium.org

[cco3, 2017-01-26 18:47:31]

The patchset sent to the CQ was uploaded after l-g-t-m from
mariakhomenko@chromium.org
Link to the patchset: https://codereview.chromium.org/2655463008/#ps80001
(title: "Rebase")

[commit-bot: I haz the power, 2017-01-26 18:48:11]

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, 2017-01-26 19:35:25]

CQ is committing da patch.

Bot data: {"patchset_id": 80001, "attempt_start_ts": 1485456451419770,
"parent_rev": "39d97d6645829da8b4c402b3112c81ebbe53004d", "commit_rev":
"5b52d760b18cc7b955ee0bf35cdfe7239f9ba0c7"}

[commit-bot: I haz the power, 2017-01-26 19:36:12]

Description was changed from

==========
Add new pattern for creating downstream objects

This change introduces a new pattern for instantiating objects of
classes that have have differing upstream/downstream implementations.
If a class's constructor requires no parameters (as is most frequently
the case in this scenario), it can be created with:

    ChromeApplication.createObject(MyType.class);

And registered with no additional change upstream, and only a small
implementation (that does not require creating additional methods)
downstream.  Without this change, one must register a new method both
upstream and downstream as well as cast an application context to a
ChromeApplication before calling that newly registered return
type-specifc method.

BUG=685383
==========

to

==========
Add new pattern for creating downstream objects

This change introduces a new pattern for instantiating objects of
classes that have have differing upstream/downstream implementations.
If a class's constructor requires no parameters (as is most frequently
the case in this scenario), it can be created with:

    ChromeApplication.createObject(MyType.class);

And registered with no additional change upstream, and only a small
implementation (that does not require creating additional methods)
downstream.  Without this change, one must register a new method both
upstream and downstream as well as cast an application context to a
ChromeApplication before calling that newly registered return
type-specifc method.

BUG=685383

Review-Url: https://codereview.chromium.org/2655463008
Cr-Commit-Position: refs/heads/master@{#446394}
Committed:
https://chromium.googlesource.com/chromium/src/+/5b52d760b18cc7b955ee0bf35cdf...
==========

[commit-bot: I haz the power, 2017-01-26 19:36:14]

Committed patchset #5 (id:80001) as
https://chromium.googlesource.com/chromium/src/+/5b52d760b18cc7b955ee0bf35cdf...