sync: Add UI code for per type debug counters

chrome/browser/resources/sync_internals/types.html

Index: chrome/browser/resources/sync_internals/types.html
diff --git a/chrome/browser/resources/sync_internals/types.html b/chrome/browser/resources/sync_internals/types.html
new file mode 100644
index 0000000000000000000000000000000000000000..03e92b32cebb64f6cd10211593785da2340da53e
--- /dev/null
+++ b/chrome/browser/resources/sync_internals/types.html
@@ -0,0 +1,51 @@
+  <div id="type-counters-container-wrapper" jsskip="true">
+    <div class="section">
+      <h2>Type Counters</h2>
+      <table id="type-counters-table">
+        <thead>
+          <tr>
+            <th class='type'>Type</th>
+            <th>Total Entries</th>
+
+            <th>Updates Received</th>
+            <th>Reflected Updates Received</th>
+            <th>Tombstone Updates Received</th>
+
+            <th>Updates Applied</th>
+            <th>Hierarchy Conflict Application Failures</th>
+            <th>Encryption Conflict Application Failures</th>
+
+            <th>Server Overwrite Conflict</th>

[maniscalco, 2014/05/23 00:55:00]

Is this a count? should it read Conflicts" instead of "Conflict"?  Same goes for
one line down.

[rlarocque, 2014/05/27 20:13:26]

Right, it should be plural.

These are meant to indicate "There was a conflict, and it was resolved in favor
of the {server,client}".  Let me know if you can think of a better way to name
it.

+            <th>Local Overwrite Conflict</th>
+
+            <th>Commit Attempts</th>
+            <th>Commit Successes</th>
+            <th>Commit Conflicts</th>
+            <th>Commit Errors</th>
+          </tr>
+        </thead>
+        <tbody>
+          <tr jsselect="rows">
+            <td jscontent="type"></td>
+            <td jscontent="counters.numEntries || 0">0</td>

[maniscalco, 2014/05/23 00:55:00]

What does the || 0 do?

[rlarocque, 2014/05/27 20:13:26]

It's a bit of a hack to initialize the table to show all zeroes if the
information we're looking for hasn't been received yet.

If counters.numEntries is "falsy", the || expression will return the second
argument (0).  Things like false, null, undefined, and NaN are considered
"falsy".  The 0 value is also falsy, but that's not a big issue since the
short-circuit will end up giving us back a zero value anyway.

The alternatives would be to leave the <td> entries blank if no data has been
received yet, or to initialize the map on the JavaScript side to all zeroes. 
The latter sounds like a good idea, until you realize it means that these names
need to be specified (and kept up to date) in yet another file.

[maniscalco, 2014/05/27 20:31:07]

I see.  Thanks for the explanation.  Using "|| 0" here makes sense to me.

On 2014/05/27 20:13:26, rlarocque wrote:

+
+            <td jscontent="counters.numUpdatesReceived || 0">0</td>
+            <td jscontent="counters.numReflectedUpdatesReceived || 0">0</td>
+            <td jscontent="counters.numTombstoneUpdatesReceived || 0">0</td>
+
+            <td jscontent="counters.numUpdatesApplied || 0">0</td>
+            <td jscontent="counters.numHierarchyConflictApplicationFailures || 0">0</td>
+            <td jscontent="counters.numEncryptionConflictApplicationFailures || 0">0</td>
+
+            <td jscontent="counters.numServerOverwrites || 0">0</td>
+            <td jscontent="counters.numLocalOverwrites || 0">0</td>
+
+            <td jscontent="counters.numCommitsAttempted || 0">0</td>
+            <td jscontent="counters.numCommitsSuccess || 0">0</td>
+            <td jscontent="counters.numCommitsConflict || 0">0</td>
+            <td jscontent="counters.numCommitsError || 0">0</td>
+          </tr>
+        </tbody>
+      </table>
+    </div>
+  </div>