Add a new UMA enum to record how many download uses parallel requests

Add a new UMA enum to record how many download uses parallel requests

Only download item knows whether the internal state is INITIAL_INTERNAL
So if we record the UMA in parallelDownloadJob, it could cause a multiple counting issue.

BUG=644352
Review-Url: https://codereview.chromium.org/2762943003
Cr-Commit-Position: refs/heads/master@{#458977}
Committed: https://chromium.googlesource.com/chromium/src/+/1c18f0dfcf0e06987105d4aed02449328ef5d893

[qinmin, 2017-03-21 23:34:38]

qinmin@chromium.org changed reviewers:
+ dtrainor@chromium.org, isherman@chromium.org, xingliu@chromium.org

[qinmin, 2017-03-21 23:34:39]

PTAL

[xingliu, 2017-03-21 23:39:13]

lgtm.

[Ilya Sherman, 2017-03-22 00:20:31]

histograms.xml lgtm

[David Trainor- moved to gerrit, 2017-03-22 03:15:25]

lgtm

[qinmin, 2017-03-22 05:50:50]

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

[commit-bot: I haz the power, 2017-03-22 05:51:27]

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, 2017-03-22 05:54:14]

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

[commit-bot: I haz the power, 2017-03-22 05:54:15]

Dry run: Try jobs failed on following builders:
  chromium_presubmit on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)
  ios-device on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device/builds...)
  ios-device-xcode-clang on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device-xcode-...)

[qinmin, 2017-03-22 19:14:51]

The CQ bit was checked by qinmin@chromium.org

[qinmin, 2017-03-22 19:14:52]

The patchset sent to the CQ was uploaded after l-g-t-m from
dtrainor@chromium.org, isherman@chromium.org, xingliu@chromium.org
Link to the patchset: https://codereview.chromium.org/2762943003/#ps20001
(title: "rebase")

[commit-bot: I haz the power, 2017-03-22 19:15:33]

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, 2017-03-22 21:14:50]

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

[commit-bot: I haz the power, 2017-03-22 21:14:56]

Failed to apply patch for content/browser/download/download_job.h:
While running git apply --index -p1;
  error: patch failed: content/browser/download/download_job.h:40
  error: content/browser/download/download_job.h: patch does not apply

Patch:       content/browser/download/download_job.h
Index: content/browser/download/download_job.h
diff --git a/content/browser/download/download_job.h
b/content/browser/download/download_job.h
index
532447a9e7cf9119ce9690c4ee061593f95ced3b..a25b60a9ec4b063723fbb06b893d3fc10fcb0070
100644
--- a/content/browser/download/download_job.h
+++ b/content/browser/download/download_job.h
@@ -40,6 +40,8 @@ class CONTENT_EXPORT DownloadJob {
   // WebContents.
   virtual WebContents* GetWebContents() const = 0;
 
+  virtual bool UsesParallelRequests() const;
+
  protected:
   void StartDownload() const;

[qinmin, 2017-03-22 23:24:31]

The CQ bit was checked by qinmin@chromium.org

[qinmin, 2017-03-22 23:24:32]

The patchset sent to the CQ was uploaded after l-g-t-m from
dtrainor@chromium.org, isherman@chromium.org, xingliu@chromium.org
Link to the patchset: https://codereview.chromium.org/2762943003/#ps40001
(title: "rebase again")

[commit-bot: I haz the power, 2017-03-22 23:25:19]

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, 2017-03-23 02:01:13]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1490225071624610,
"parent_rev": "3fc22c0420d457ac742c44b4e6ee4202acc645be", "commit_rev":
"1c18f0dfcf0e06987105d4aed02449328ef5d893"}

[commit-bot: I haz the power, 2017-03-23 02:01:57]

Description was changed from

==========
Add a new UMA enum to record how many download uses parallel requests

Only download item knows whether the internal state is INITIAL_INTERNAL
So if we record the UMA in parallelDownloadJob, it could cause a multiple
counting issue.

BUG=644352
==========

to

==========
Add a new UMA enum to record how many download uses parallel requests

Only download item knows whether the internal state is INITIAL_INTERNAL
So if we record the UMA in parallelDownloadJob, it could cause a multiple
counting issue.

BUG=644352

Review-Url: https://codereview.chromium.org/2762943003
Cr-Commit-Position: refs/heads/master@{#458977}
Committed:
https://chromium.googlesource.com/chromium/src/+/1c18f0dfcf0e06987105d4aed024...
==========

[commit-bot: I haz the power, 2017-03-23 02:01:58]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/1c18f0dfcf0e06987105d4aed024...