Updates the histograms for IMF and IMEs according to the new design.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 24817c5c580c28af1f7d487adf04e43b564bf812..afcffc09ca92b846a880e0b2f69a734e3c764bb6 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -9707,6 +9707,41 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>The type of Vary header for a given GET response.</summary>
 </histogram>
 
+<histogram name="IME.Commit.Index">
+  <owner>shuchen@chromium.org</owner>
+  <summary>
+    The suggestion index of the suggestion list which user chooses to commit.

[Ilya Sherman, 2014/09/16 00:00:29]

nit: "of the suggestion list" -> "of the suggestion list item"

[Shu Chen, 2014/09/16 16:36:30]

Done.

+  </summary>
+</histogram>
+
+<histogram name="IME.Commit.Type" enum="IMECommitType">
+  <owner>shuchen@chromium.org</owner>
+  <summary>
+    The suggestion accuracy type which user chooses to commit. 0: User types X,
+    and chooses X as top suggestion. 1: User types X, and chooses Y as top
+    suggestion. 2: User types X, and chooses X as non-top suggestion. 3: User
+    types X, and chooses Y as non-top suggestion. 4: User chooses a prediction
+    suggestion. 5: User reverts the committed text.

[Ilya Sherman, 2014/09/16 00:00:30]

nit: It might be more appropriate to move the bucket explanations into the enum.
 You can write an enum value as

<int value="0" label="short label">Long textual explanation that's shown on
mouse hover</int>

[Shu Chen, 2014/09/16 16:36:30]

Done.

+  </summary>
+</histogram>
+
+<histogram name="IME.VK.InitLatency" units="milliseconds">

[Ilya Sherman, 2014/09/16 00:00:29]

nit: I'd prefer that you use "VirtualKeyboard" rather than "VK".  In general,
it's preferable to spell out acronyms, since not everyone on the team is going
to be familiar with the acronyms that you use.

[Shu Chen, 2014/09/16 16:36:30]

Done.

+  <owner>shuchen@chromium.org</owner>
+  <summary>
+    The on-screen keyboard initialization latency in milliseconds.
+  </summary>
+</histogram>
+
+<histogram name="IME.VK.Layout" enum="IMEVKLayout">
+  <owner>shuchen@chromium.org</owner>
+  <summary>The usage for active layout of on-screen keyboard.</summary>

[Ilya Sherman, 2014/09/16 00:00:29]

nit: Please rephrase to something like "The layout of the on-screen keyboard.
Logged when [insert condition here]."  For "[insert condition here]", I'm
guessing it's something like "the keyboard is shown or the layout is changed",
but if it's something else, please describe that.

[Shu Chen, 2014/09/16 16:36:31]

Done.

+</histogram>
+
+<histogram name="IME.VK.LayoutSwitch">
+  <owner>shuchen@chromium.org</owner>
+  <summary>The count of switching layouts on the on-screen keyboard.</summary>

[Ilya Sherman, 2014/09/16 00:00:29]

I don't understand what this means.  It would probably help to document when
this is logged, and what the count is relative to (i.e. when, if ever, the count
is reset back to 0).

[Shu Chen, 2014/09/16 16:36:30]

Done.

+</histogram>
+
 <histogram name="Import.ImporterType.AutoImport" enum="ImporterType">
   <owner>gab@chromium.org</owner>
   <summary>The importer used on first run Auto Import.</summary>
@@ -9861,6 +9896,34 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="InputMethod.ActiveCount">

[Ilya Sherman, 2014/09/16 00:00:29]

What is the difference between "IME" and "InputMethod"?  Can we group these
histograms together under a single prefix?

[Shu Chen, 2014/09/16 16:36:30]

"InputMethod" prefix is for histograms logged in IMF (Input Method Framework) of
Chrome OS.
"IME" prefix is for histograms logged in IME extension JS through metricsPrivate
API.

[Ilya Sherman, 2014/09/16 21:51:48]

It's best not to introduce too many top-level names (prefixes), so I'll strongly
encourage you to combine these two sets of histograms under a single prefix.  If
you think it's useful to distinguish them, you can use secondary prefixes, e.g.
"Input.IME.*" and "Input.InputMethod.*".

[Shu Chen, 2014/09/17 15:17:28]

Done.

+  <owner>shuchen@chromium.org</owner>
+  <summary>
+    The number of active input methods recorded when user is logged in to CrOS.

[Ilya Sherman, 2014/09/16 00:00:29]

nit: "when user is logged in to CrOS" -> "when the user logs in to Chrome OS".

[Ilya Sherman, 2014/09/16 00:00:29]

What is an "input method", exactly?  Is it the number of virtual keyboard
layouts the that the user has enabled?

[Ilya Sherman, 2014/09/16 00:00:30]

nit: "input methods recorded when" -> "input methods. Recorded when"

[Shu Chen, 2014/09/16 16:36:30]

Done.

[Shu Chen, 2014/09/16 16:36:30]

it's not only for virtual keyboard but also for physical keyboard.

for example, a typical chinese pinyin input method user will enable both US
keyboard and Chinese Pinyin IME.
So when she logs in to Chrome OS, the active input method count is 2.

[Shu Chen, 2014/09/16 16:36:31]

Done.

[Ilya Sherman, 2014/09/16 21:51:48]

I think this would be useful to clarify in the histogram's <summary>.

[Shu Chen, 2014/09/17 15:17:28]

Done.

+  </summary>
+</histogram>
+
+<histogram name="InputMethod.Category" enum="InputMethodCategory">
+  <owner>shuchen@chromium.org</owner>
+  <summary>
+    The breakdown of input method usage by input method category, which is

[Ilya Sherman, 2014/09/16 00:00:29]

nit: ", which is recorded" -> ". Recorded"

[Shu Chen, 2014/09/16 16:36:31]

Done.

+    recorded when user presses keys on physical or on-screen keyboard.

[Ilya Sherman, 2014/09/16 00:00:29]

So, this is recorded once per key press?

[Ilya Sherman, 2014/09/16 00:00:30]

nit: "user" -> "the user"

[Shu Chen, 2014/09/16 16:36:30]

I've changed the meaning. Please let me know whether it's still confusing.

[Shu Chen, 2014/09/16 16:36:31]

Done.

+  </summary>
+</histogram>
+
+<histogram name="InputMethod.CommitLength">
+  <owner>shuchen@chromium.org</owner>
+  <summary>The number of characters committed with composition text.</summary>
+</histogram>
+
+<histogram name="InputMethod.ID">
+  <owner>shuchen@chromium.org</owner>
+  <summary>
+    The breakdown of input method usage by input method IDs, which is recorded

[Ilya Sherman, 2014/09/16 00:00:29]

nit: ", which is recorded" -> ". Recorded"

[Shu Chen, 2014/09/16 16:36:30]

Done.

+    when user presses keys on physical or on-screen keyboard.

[Ilya Sherman, 2014/09/16 00:00:29]

I don't really understand what these IDs look like.  Could you associate an enum
with this histogram?

[Ilya Sherman, 2014/09/16 00:00:29]

nit: "user" -> "the user"

[Shu Chen, 2014/09/16 16:36:30]

Done.

[Shu Chen, 2014/09/16 16:36:30]

Please check the comment at line 262 in input_method_manager_impl.h.
Can I not create the enum for the IDs? It would be a long list.

[Shu Chen, 2014/09/16 16:36:31]

Please check the comment at line 262 in input_method_manager_impl.h.
Can I not create the enum for the IDs? It would be a long list.

[Ilya Sherman, 2014/09/16 21:51:48]

You don't need to generate an enum in C++, but it would be very helpful to have
semantically meaningful labels on the histograms dashboard.  It doesn't seem
like it should be too hard to write a script that would generate all possible
enum values with some reasonably small upper-bound on the index (the third part
of the tuple).

[Shu Chen, 2014/09/17 15:17:27]

Done.

+  </summary>
+</histogram>
+
 <histogram name="Installer.AttemptsCount.Total" units="count">
   <owner>zeuthen@chromium.org</owner>
   <summary>
@@ -43426,6 +43489,25 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </int>
 </enum>
 
+<enum name="IMECommitType" type="int">
+  <int value="0" label="X -&gt; X(0)"/>
+  <int value="1" label="X -&gt; Y(0)"/>
+  <int value="2" label="X -&gt; X(1)"/>
+  <int value="3" label="X -&gt; Y(1)"/>

[Ilya Sherman, 2014/09/16 00:00:29]

nit: "(0)" and "(1)" are not very clear, IMO.  Are there any other
representations that you can think of that might be a little clearer?

[Shu Chen, 2014/09/16 16:36:30]

Done.

+  <int value="4" label="Prediction"/>
+  <int value="5" label="Revert"/>
+</enum>
+
+<enum name="IMEVKLayout" type="int">
+  <int value="0" label="Compact"/>
+  <int value="1" label="CompactSymbol"/>
+  <int value="2" label="CompactMore"/>

[Ilya Sherman, 2014/09/16 00:00:29]

Optional nit: WDYT of something like "Compact w/ symbols" and "Extra compact"
(assuming that's what the third item means)?

[Shu Chen, 2014/09/16 16:36:31]

I would prefer to use them as it is used in discussions, designs and coding.

+  <int value="3" label="Full"/>
+  <int value="4" label="A11y"/>
+  <int value="5" label="Handwriting"/>
+  <int value="6" label="Emoji"/>
+</enum>
+
 <enum name="ImporterType" type="int">
   <int value="0" label="Unknown"/>
   <int value="1" label="IMPORTER_METRICS_IE">IE (Windows-only)</int>
@@ -43481,6 +43563,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="4" label="Script"/>
 </enum>
 
+<enum name="InputMethodCategory" type="int">
+  <int value="0" label="XKB"/>

[Ilya Sherman, 2014/09/16 00:00:29]

Isn't there an UNK(nown) bucket?

[Shu Chen, 2014/09/16 16:36:31]

Done.

+  <int value="1" label="ZH"/>
+  <int value="2" label="JA"/>
+  <int value="3" label="KO"/>
+  <int value="4" label="M17N"/>
+  <int value="5" label="T13N"/>

[Ilya Sherman, 2014/09/16 00:00:30]

These labels are super cryptic.  Can you use less cryptic labels?

[Shu Chen, 2014/09/16 16:36:30]

Done.

+</enum>
+
 <enum name="InstantControllerEvent" type="int">
   <int value="0" label="URL_ADDED_TO_BLACKLIST"/>
   <int value="1" label="URL_REMOVED_FROM_BLACKLIST"/>
@@ -52716,6 +52807,34 @@ To add a new entry, add it with any value and run test to compute valid value.
   <affected-histogram name="PLT.BeginToFinish_NormalLoad"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="IMEAutoCorrect" separator=".">
+  <affected-histogram name="IME.Commit.Index.FR"/>

[Ilya Sherman, 2014/09/16 00:00:29]

Hmm, why is this histogram not listed together with the other three, below?

[Shu Chen, 2014/09/16 16:36:30]

Done.

+  <suffix name="AC0" label="The auto-correct level is 0"/>
+  <suffix name="AC1" label="The auto-correct level is 1"/>
+  <suffix name="AC2" label="The auto-correct level is 2"/>
+  <affected-histogram name="IME.Commit.Index.US"/>
+  <affected-histogram name="IME.Commit.Type.FR"/>
+  <affected-histogram name="IME.Commit.Type.US"/>
+</histogram_suffixes>
+
+<histogram_suffixes name="IMEMajorNames" separator=".">
+  <suffix name="US" label="The US keyboard input method"/>
+  <suffix name="FR" label="The French keyboard input method"/>
+  <suffix name="Pinyin" label="The Chinse Pinyin input method"/>
+  <affected-histogram name="IME.Commit.Index"/>
+  <affected-histogram name="IME.Commit.Type"/>
+</histogram_suffixes>
+
+<histogram_suffixes name="IMEVKLatency" separator=".">
+  <suffix name="BackgroundSettingsFetched" label="BackgroundSettingsFetched"/>
+  <suffix name="HtmlLoaded" label="HtmlLoaded"/>
+  <suffix name="KeyboardCreated" label="KeyboardCreated"/>
+  <suffix name="KeyboardShown" label="KeyboardShown"/>
+  <suffix name="KeysetLoaded" label="KeyboardLoaded"/>
+  <suffix name="LayoutLoaded" label="LayoutLoaded"/>

[Ilya Sherman, 2014/09/16 00:00:29]

nit: These labels will be appended to the histogram summary, so please format
them as English sentences.

[Shu Chen, 2014/09/16 16:36:30]

Done.

+  <affected-histogram name="IME.VK.InitLatency"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="IndexedDBLevelDBErrnoMethods" separator=".">
   <suffix name="NewLogger" label="ChromiumEnv::NewLogger"/>
   <suffix name="NewSequentialFile" label="ChromiumEnv::NewSequentialFile"/>