webview: UMA for WebSettings.setLayoutAlgorithm.

Add a UMA histogram to record the layout algorithm being requested by
apps which call WebSettings.setLayoutHistogram, in preparation for
potentially deprecating/removing text autosizing.

Bug: 391990606
Change-Id: I32bd665541bd0909cfa8a5add5ac4b38e5ab4a04
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6642582
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Peter Beverloo <peter@chromium.org>
Auto-Submit: Richard (Torne) Coles <torne@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1474827}

android_webview/java/src/org/chromium/android_webview/AwSettings.java

diff --git a/android_webview/java/src/org/chromium/android_webview/AwSettings.java b/android_webview/java/src/org/chromium/android_webview/AwSettings.java
index 37eadbea..bb9506a4 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwSettings.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwSettings.java
@@ -85,6 +85,7 @@
     /* See {@link android.webkit.WebSettings}. */
     public static final int LAYOUT_ALGORITHM_NARROW_COLUMNS = 2;
     public static final int LAYOUT_ALGORITHM_TEXT_AUTOSIZING = 3;
+    private static final int LAYOUT_ALGORITHM_COUNT = 4;
 
     public static final int FORCE_DARK_OFF = ForceDarkMode.FORCE_DARK_OFF;
     public static final int FORCE_DARK_AUTO = ForceDarkMode.FORCE_DARK_AUTO;
@@ -1304,6 +1305,8 @@
     /** See {@link android.webkit.WebSettings#setLayoutAlgorithm}. */
     public void setLayoutAlgorithm(@LayoutAlgorithm int l) {
         if (TRACE) Log.i(TAG, "setLayoutAlgorithm=" + l);
+        RecordHistogram.recordEnumeratedHistogram(
+                "Android.WebView.SetLayoutAlgorithm", l, LAYOUT_ALGORITHM_COUNT);
         synchronized (mAwSettingsLock) {
             if (mLayoutAlgorithm != l) {
                 mLayoutAlgorithm = l;

tools/metrics/histograms/metadata/android/enums.xml

diff --git a/tools/metrics/histograms/metadata/android/enums.xml b/tools/metrics/histograms/metadata/android/enums.xml
index 4e5685a..5ef0a6e 100644
--- a/tools/metrics/histograms/metadata/android/enums.xml
+++ b/tools/metrics/histograms/metadata/android/enums.xml
@@ -2431,6 +2431,13 @@
   <int value="5" label="WebView light, night mode off"/>
 </enum>
 
+<enum name="WebViewLayoutAlgorithm">
+  <int value="0" label="NORMAL"/>
+  <int value="1" label="SINGLE_COLUMN"/>
+  <int value="2" label="NARROW_COLUMNS"/>
+  <int value="3" label="TEXT_AUTOSIZING"/>
+</enum>
+
 <enum name="WebViewMixedContentMode">
   <int value="0" label="Always allow"/>
   <int value="1" label="Never allow"/>

tools/metrics/histograms/metadata/android/histograms.xml

diff --git a/tools/metrics/histograms/metadata/android/histograms.xml b/tools/metrics/histograms/metadata/android/histograms.xml
index 74949571..138fd10 100644
--- a/tools/metrics/histograms/metadata/android/histograms.xml
+++ b/tools/metrics/histograms/metadata/android/histograms.xml
@@ -8121,6 +8121,16 @@
   </summary>
 </histogram>
 
+<histogram name="Android.WebView.SetLayoutAlgorithm"
+    enum="WebViewLayoutAlgorithm" expires_after="2027-12-01">
+  <owner>torne@chromium.org</owner>
+  <owner>src/android_webview/OWNERS</owner>
+  <summary>
+    Records the layout algorithm requested in each call to
+    WebSettings.setLayoutAlgorithm().
+  </summary>
+</histogram>
+
 <histogram
     name="Android.WebView.ShouldInterceptRequest.Async.CallbackLeakedWithoutResponse"
     enum="Boolean" expires_after="2026-03-10">