Use LoadLibraryExW if applicable in LoadNativeLibrary on Windows

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 a61d57ec74803a23df4b7a9418c169f5d7fc6e6c..32920d7f70faaf6c0891b50fd00bf3d74a4729e2 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -24514,6 +24514,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="LibraryLoader.NativeLibraryDynamicallyLoad"
+    enum="LoadLibraryResultCategory">
+  <owner>chengx@chromium.org</owner>
+  <summary>
+    This metric records the LoadLibraryExW and LoadLibraryW Windows API call
+    results, which are used  in LoadNativeLibraryDynamically method in
+    native_library_win.cc.
+  </summary>
+</histogram>
+
 <histogram name="LibraryLoader.NativeLibraryHack" enum="BooleanUsage">
   <obsolete>
     Deprecated as of 11/2014, removed from code.
@@ -98778,6 +98788,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="23" label="Unnamed"/>
 </enum>
 
+<enum name="LoadLibraryResultCategory" type="int">
+  <int value="0" label="LoadLibExW Succeed"/>
+  <int value="1" label="LoadLibExW Fail, LoadLibW Succeed"/>
+  <int value="2" label="LoadLibExW Fail, LoadLibW Fail"/>
+  <int value="3" label="LoadLibExW Unavailable, LoadLibW Succeed"/>
+  <int value="4" label="LoadLibExW Unavailable, LoadLibW Fail"/>
+</enum>
+
 <enum name="LoadType" type="int">
   <int value="0" label="UNDEFINED_LOAD">Not yet initialized</int>
   <int value="1" label="RELOAD">User pressed reload</int>