DevTools: fix exception when setting a breakpoint in sourcemap source

DevTools: fix exception when setting a breakpoint in sourcemap source

The following scenario takes place on reload:
1. The breakpoint gets hit in dist.js
2. The dist.js has a sourceMap which is not yet loaded. For this reason,
   stubs are created for the sourcemaps sources. SourceMapping gets changed
   to actually point to the stub
3. The execution line gets revealed in the stub
4. JavaScriptSourceFrame attempts to put a breakpoint in a stub. However,
   since the stub is just a few lines of text, there's no linehandle for the
   breakpoint linenumber.

This is essentially an issue inside TextPositionPositionHandle.

BUG=668242
TBR=kozyatinskiy, dgozman

Committed: https://crrev.com/b33d093abe57100f572b4901dbcfac5d5489f121
Cr-Commit-Position: refs/heads/master@{#434262}

[lushnikov, 2016-11-23 20:06:34]

Description was changed from

==========
fix breakpoints exception

BUG=
==========

to

==========
DevTools: fix exception when setting a breakpoint in sourcemap source

The following scenario takes place on reload:
1. The breakpoint gets hit in dist.js
2. The dist.js has a sourceMap which is not yet loaded. For this reason,
   stubs are created for the sourcemaps sources. SourceMapping gets changed
   to actually point to the stub
3. The execution line gets revealed in the stub
4. JavaScriptSourceFrame attempts to put a breakpoint in a stub. However,
   since the stub is just a few lines of text, there's no linehandle for the 
   breakpoint linenumber.

This is essentially an issue inside TextPositionPositionHandle.

BUG=668242
TBR=kozyatinskiy, dgozman
==========

[lushnikov, 2016-11-23 20:06:34]

lushnikov@chromium.org changed reviewers:
+ dgozman@chromium.org, kozyatinskiy@chromium.org

[lushnikov, 2016-11-23 20:06:51]

The CQ bit was checked by lushnikov@chromium.org

[commit-bot: I haz the power, 2016-11-23 20:07:33]

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, 2016-11-23 22:01:15]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1479931611389710, "parent_rev":
"9b369eb7f33fcb5b3e593d452f348e3ab6a0aa60", "commit_rev":
"aa23c04d7d2cecf7369590c94787eb70da3a79f6"}

[commit-bot: I haz the power, 2016-11-23 22:01:42]

Description was changed from

==========
DevTools: fix exception when setting a breakpoint in sourcemap source

The following scenario takes place on reload:
1. The breakpoint gets hit in dist.js
2. The dist.js has a sourceMap which is not yet loaded. For this reason,
   stubs are created for the sourcemaps sources. SourceMapping gets changed
   to actually point to the stub
3. The execution line gets revealed in the stub
4. JavaScriptSourceFrame attempts to put a breakpoint in a stub. However,
   since the stub is just a few lines of text, there's no linehandle for the 
   breakpoint linenumber.

This is essentially an issue inside TextPositionPositionHandle.

BUG=668242
TBR=kozyatinskiy, dgozman
==========

to

==========
DevTools: fix exception when setting a breakpoint in sourcemap source

The following scenario takes place on reload:
1. The breakpoint gets hit in dist.js
2. The dist.js has a sourceMap which is not yet loaded. For this reason,
   stubs are created for the sourcemaps sources. SourceMapping gets changed
   to actually point to the stub
3. The execution line gets revealed in the stub
4. JavaScriptSourceFrame attempts to put a breakpoint in a stub. However,
   since the stub is just a few lines of text, there's no linehandle for the 
   breakpoint linenumber.

This is essentially an issue inside TextPositionPositionHandle.

BUG=668242
TBR=kozyatinskiy, dgozman
==========

[commit-bot: I haz the power, 2016-11-23 22:01:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-23 22:03:29]

Description was changed from

==========
DevTools: fix exception when setting a breakpoint in sourcemap source

The following scenario takes place on reload:
1. The breakpoint gets hit in dist.js
2. The dist.js has a sourceMap which is not yet loaded. For this reason,
   stubs are created for the sourcemaps sources. SourceMapping gets changed
   to actually point to the stub
3. The execution line gets revealed in the stub
4. JavaScriptSourceFrame attempts to put a breakpoint in a stub. However,
   since the stub is just a few lines of text, there's no linehandle for the 
   breakpoint linenumber.

This is essentially an issue inside TextPositionPositionHandle.

BUG=668242
TBR=kozyatinskiy, dgozman
==========

to

==========
DevTools: fix exception when setting a breakpoint in sourcemap source

The following scenario takes place on reload:
1. The breakpoint gets hit in dist.js
2. The dist.js has a sourceMap which is not yet loaded. For this reason,
   stubs are created for the sourcemaps sources. SourceMapping gets changed
   to actually point to the stub
3. The execution line gets revealed in the stub
4. JavaScriptSourceFrame attempts to put a breakpoint in a stub. However,
   since the stub is just a few lines of text, there's no linehandle for the
   breakpoint linenumber.

This is essentially an issue inside TextPositionPositionHandle.

BUG=668242
TBR=kozyatinskiy, dgozman

Committed: https://crrev.com/b33d093abe57100f572b4901dbcfac5d5489f121
Cr-Commit-Position: refs/heads/master@{#434262}
==========

[commit-bot: I haz the power, 2016-11-23 22:03:30]

Patchset 1 (id:??) landed as
https://crrev.com/b33d093abe57100f572b4901dbcfac5d5489f121
Cr-Commit-Position: refs/heads/master@{#434262}