Add UMA metrics to track the source of homescreen icons on launch.

Add UMA metrics to track the source of homescreen icons on launch.

Currently, it is impossible to distinguish between launches from
homescreen icons added via app banners or the menu item. This CL adds an
additional value to the intent saved on homescreen icons. The value
corresponds to the source of the icon: whether it was added via the add
to homescreen menu item, via an app install, banner, or from an unknown
source (all intents added prior to this CL). The additional metric
allows for the effectiveness of web app install banners on Android to be
measured.

BUG=486177
Committed: https://crrev.com/32fe3048050916028ac902abd0d7db9de4263e0b
Cr-Commit-Position: refs/heads/master@{#337701}

[dominickn, 2015-07-03 05:20:07]

dominickn@chromium.org changed reviewers:
+ dfalcantara@chromium.org

[dominickn, 2015-07-03 05:20:44]

dominickn@chromium.org changed reviewers:
+ isherman@chromium.org, tedchoc@chromium.org

[dominickn, 2015-07-03 05:21:19]

dominickn@chromium.org changed reviewers:
- dfalcantara@chromium.org

[dominickn, 2015-07-03 07:37:17]

Ilya: please review histograms.xml
Ted: please review everything else

Thanks!

[Ilya Sherman, 2015-07-03 18:11:45]

histograms lgtm % a nit:

https://codereview.chromium.org/1220813010/diff/20001/chrome/browser/android/...
File chrome/browser/android/shortcut_info.h (right):

https://codereview.chromium.org/1220813010/diff/20001/chrome/browser/android/...
chrome/browser/android/shortcut_info.h:15: enum Source {
Please document that this is used to back an UMA histogram, and therefore should
be treated as append-only.

https://codereview.chromium.org/1220813010/diff/20001/tools/metrics/histogram...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1220813010/diff/20001/tools/metrics/histogram...
tools/metrics/histograms/histograms.xml:59370: +  <int value="0" label="Home
screen shortcut source unknown"/>
nit: These labels are going to be displayed as the left column of a tabular
layout, so shorter labels are better.  For example, I'd shorten this to just
"Unknown".

[dominickn, 2015-07-05 23:33:18]

https://codereview.chromium.org/1220813010/diff/20001/chrome/browser/android/...
File chrome/browser/android/shortcut_info.h (right):

https://codereview.chromium.org/1220813010/diff/20001/chrome/browser/android/...
chrome/browser/android/shortcut_info.h:15: enum Source {
On 2015/07/03 18:11:45, Ilya Sherman wrote:
> Please document that this is used to back an UMA histogram, and therefore
should
> be treated as append-only.

Done.

https://codereview.chromium.org/1220813010/diff/20001/tools/metrics/histogram...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1220813010/diff/20001/tools/metrics/histogram...
tools/metrics/histograms/histograms.xml:59370: +  <int value="0" label="Home
screen shortcut source unknown"/>
On 2015/07/03 18:11:45, Ilya Sherman wrote:
> nit: These labels are going to be displayed as the left column of a tabular
> layout, so shorter labels are better.  For example, I'd shorten this to just
> "Unknown".

Done.

[Ted C, 2015-07-06 20:35:33]

tedchoc@chromium.org changed reviewers:
+ dfalcantara@chromium.org

[Ted C, 2015-07-06 20:35:33]

+dfalcantara -- he's better to review this than me.  I can add owners as needed,
but I think he should take a first pass (also he should be in all the owners
files for these, so we should fix that if his stamp isn't good enough).

[gone, 2015-07-06 21:04:22]

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/java/src...
File chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
(right):

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/java/src...
chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java:39:
public static final int SOURCE_UNKNOWN = 0;
Are there other values that may need to be synced across C++ and Java?  There's
a mechanism for automagically generating a Java file from a C++ file containing
a specially annotated enum.

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/java/src...
File
chrome/android/java/src/org/chromium/chrome/browser/metrics/LaunchMetrics.java
(right):

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/java/src...
chrome/android/java/src/org/chromium/chrome/browser/metrics/LaunchMetrics.java:18:
private static class UrlSourcePair {
android.util.Pair?

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/javatest...
File
chrome/android/javatests/src/org/chromium/chrome/browser/webapps/WebappInfoTest.java
(right):

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/javatest...
chrome/android/javatests/src/org/chromium/chrome/browser/webapps/WebappInfoTest.java:39:
null, title, ScreenOrientationValues.DEFAULT, ShortcutHelper.SOURCE_UNKNOWN);
Since you're already in here, can you add a basic unit test to make sure that
the Source is correct?

[dominickn, 2015-07-07 00:41:42]

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/java/src...
File chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
(right):

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/java/src...
chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java:39:
public static final int SOURCE_UNKNOWN = 0;
On 2015/07/06 21:04:21, dfalcantara wrote:
> Are there other values that may need to be synced across C++ and Java? 
There's
> a mechanism for automagically generating a Java file from a C++ file
containing
> a specially annotated enum.

As currently implemented, the values are sent from C++ and read in C++ - Java
only handles saving them into the intent and reading them back off before
sending back to C++. I think it's sufficient to just have this constant defined
and documented since none of the other values are currently needed in Java. This
can be revisited if the metrics implementation changes or if knowing the source
becomes important in Java.

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/java/src...
File
chrome/android/java/src/org/chromium/chrome/browser/metrics/LaunchMetrics.java
(right):

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/java/src...
chrome/android/java/src/org/chromium/chrome/browser/metrics/LaunchMetrics.java:18:
private static class UrlSourcePair {
On 2015/07/06 21:04:22, dfalcantara wrote:
> android.util.Pair?

Done. Thanks for pointing this out.

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/javatest...
File
chrome/android/javatests/src/org/chromium/chrome/browser/webapps/WebappInfoTest.java
(right):

https://codereview.chromium.org/1220813010/diff/40001/chrome/android/javatest...
chrome/android/javatests/src/org/chromium/chrome/browser/webapps/WebappInfoTest.java:39:
null, title, ScreenOrientationValues.DEFAULT, ShortcutHelper.SOURCE_UNKNOWN);
On 2015/07/06 21:04:22, dfalcantara wrote:
> Since you're already in here, can you add a basic unit test to make sure that
> the Source is correct?

Done.

[gone, 2015-07-07 00:54:43]

lgtm

[Ted C, 2015-07-07 20:16:51]

On 2015/07/07 00:54:43, dfalcantara wrote:
> lgtm

owners - lgtm

[dominickn, 2015-07-07 21:36:25]

The CQ bit was checked by dominickn@chromium.org

[dominickn, 2015-07-07 21:36:26]

The patchset sent to the CQ was uploaded after l-g-t-m from
isherman@chromium.org
Link to the patchset: https://codereview.chromium.org/1220813010/#ps60001
(title: "Addressing reviewer comments")

[commit-bot: I haz the power, 2015-07-07 21:38:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1220813010/60001

[commit-bot: I haz the power, 2015-07-07 22:43:02]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-07-07 22:44:02]

Patchset 4 (id:??) landed as
https://crrev.com/32fe3048050916028ac902abd0d7db9de4263e0b
Cr-Commit-Position: refs/heads/master@{#337701}