Null check ContentViewCore::GetJavaObject

Null check ContentViewCore::GetJavaObject

ContentViewCoreImpl holds a weak reference to the java peer. This means
reference returned by GetJavaObject may be null.

Go through all callers of this API and make sure they correctly handle
null reference.

BUG=469803
Committed: https://crrev.com/684ba03ae718cb7ffa9dc0720d011f941c084da3
Cr-Commit-Position: refs/heads/master@{#324243}

[boliu, 2015-04-08 15:53:55]

boliu@chromium.org changed reviewers:
+ gunsch@chromium.org, tedchoc@chromium.org

[boliu, 2015-04-08 15:53:56]

tedchoc: content and components (I was trying to find someone else, but Ted, you
own everything!)
gunsch: chromecast

[Ted C, 2015-04-08 15:59:36]

lgtm

https://codereview.chromium.org/1067023005/diff/40001/content/browser/android...
File content/browser/android/content_video_view.cc (right):

https://codereview.chromium.org/1067023005/diff/40001/content/browser/android...
content/browser/android/content_video_view.cc:198: JavaObjectWeakGlobalRef
ContentVideoView::CreateJavaObject() {
do the callers of this properly null check?

[boliu, 2015-04-08 16:04:29]

https://codereview.chromium.org/1067023005/diff/40001/content/browser/android...
File content/browser/android/content_video_view.cc (right):

https://codereview.chromium.org/1067023005/diff/40001/content/browser/android...
content/browser/android/content_video_view.cc:198: JavaObjectWeakGlobalRef
ContentVideoView::CreateJavaObject() {
On 2015/04/08 15:59:36, Ted C wrote:
> do the callers of this properly null check?

Yes. See content_video_view.is_null() throughout this file

Btw, do you think this is a better pattern for returning a java weak reference,
and make the caller dereference it? That duplicates the dereference code in all
callers though which sucks.

I think we need a ScopedJavaLocalRefFromWeakRef or something :/

[gunsch, 2015-04-08 16:17:21]

lgtm for chromecast

[boliu, 2015-04-08 16:20:24]

The CQ bit was checked by boliu@chromium.org

[commit-bot: I haz the power, 2015-04-08 16:20:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1067023005/40001

[commit-bot: I haz the power, 2015-04-08 17:07:26]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-04-08 17:09:10]

Patchset 3 (id:??) landed as
https://crrev.com/684ba03ae718cb7ffa9dc0720d011f941c084da3
Cr-Commit-Position: refs/heads/master@{#324243}

[Ted C, 2015-04-08 17:13:50]

https://codereview.chromium.org/1067023005/diff/40001/content/browser/android...
File content/browser/android/content_video_view.cc (right):

https://codereview.chromium.org/1067023005/diff/40001/content/browser/android...
content/browser/android/content_video_view.cc:198: JavaObjectWeakGlobalRef
ContentVideoView::CreateJavaObject() {
On 2015/04/08 16:04:29, boliu wrote:
> On 2015/04/08 15:59:36, Ted C wrote:
> > do the callers of this properly null check?
> 
> Yes. See content_video_view.is_null() throughout this file
> 
> Btw, do you think this is a better pattern for returning a java weak
reference,
> and make the caller dereference it? That duplicates the dereference code in
all
> callers though which sucks.
> 
> I think we need a ScopedJavaLocalRefFromWeakRef or something :/

They are all pretty gross.  I don't really have a strong opinion about it.