Extracting more than one wallpaper prominent color

tools/metrics/histograms/enums.xml

Index: tools/metrics/histograms/enums.xml
diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
index 8a295e5af1f6c506277f40e5e40d82b8767fad03..75307abbe81517856589f2560f0bf96656071ed4 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml
@@ -37656,6 +37656,22 @@ from previous Chrome versions.
   <int value="1" label="Android Wallpapers App"/>
 </enum>
 
+<enum name="WallpaperColorExtractionResult">
+  <int value="0" label="RESULT_DARK_VIBRANT_TRANSPARENT"/>

[Ilya Sherman, 2017/06/20 23:00:00]

nit: I'd write this in the more human-friendly form of "Dark, vibrant,
transparent"; but if you really prefer to have the labels match the enum values,
that's ok too.

[Qiang(Joe) Xu, 2017/06/21 01:10:52]

I added comments to wallpaper_color_extraction_result.h. So I keep the format
here.

+  <int value="1" label="RESULT_DARK_VIBRANT_OPAQUE"/>
+  <int value="2" label="RESULT_ORMAL_VIBRANT_TRANSPARENT"/>
+  <int value="3" label="RESULT_NORMAL_VIBRANT_OPAQUE"/>
+  <int value="4" label="RESULT_LIGHT_VIBRANT_TRANSPARENT"/>
+  <int value="5" label="RESULT_LIGHT_VIBRANT_OPAQUE"/>
+  <int value="6" label="RESULT_DARK_MUTED_TRANSPARENT"/>
+  <int value="7" label="RESULT_DARK_MUTED_OPAQUE"/>
+  <int value="8" label="RESULT_NORMAL_MUTED_TRANSPARENT"/>
+  <int value="9" label="RESULT_NORMAL_MUTED_OPAQUE"/>
+  <int value="10" label="RESULT_LIGHT_MUTED_TRANSPARENT"/>
+  <int value="11" label="RESULT_LIGHT_MUTED_OPAQUE"/>
+  <int value="12" label="NUM_COLOR_EXTRACTION_RESULTS"/>

[Ilya Sherman, 2017/06/20 23:00:00]

nit: No need to list this, since it won't be recorded.

[Qiang(Joe) Xu, 2017/06/21 01:10:52]

Done.

+</enum>
+
 <enum name="WallpaperLayout">
   <int value="0" label="Center"/>
   <int value="1" label="Center Cropped"/>