[HaTS] Fix button text cases based on platforms

On Mac, we follow platform convention to use all titlecase for
button text. On other platforms, we should prefer full sentence --
non titlecase for button text. So this CL make the button text
casing depending on platforms.

BUG=979530

Change-Id: I47afe2192e65a42511b36133d0c69cb325c238af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1783240
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#692943}

chrome/app/generated_resources.grd

@@ -10028,9 +10028,16 @@ Please help our engineers fix this problem. Tell us what happened right before y
 
     <!-- User happiness tracking survey UI -->
     <if expr="not is_android">
-      <message name="IDS_HATS_BUBBLE_OK_LABEL" translateable="false" desc="Button label on Happiness Tracking Survey's invitation banner, clicking the button gives the user's consent on taking the survey.">
-        Take survey
-      </message>
+      <if expr="use_titlecase">
+        <message name="IDS_HATS_BUBBLE_OK_LABEL" translateable="false" desc="Button label on Happiness Tracking Survey's invitation banner, clicking the button gives the user's consent on taking the survey.">
+          Take Survey
+        </message>
+      </if>
+      <if expr="not use_titlecase">
+        <message name="IDS_HATS_BUBBLE_OK_LABEL" translateable="false" desc="Button label on Happiness Tracking Survey's invitation banner, clicking the button gives the user's consent on taking the survey.">
+          Take survey
+        </message>
+      </if>
       <message name="IDS_HATS_BUBBLE_TEXT" translateable="false" desc="The text in Happiness Tracking Survey's invitation banner, it explains why users should take our survey.">
         Your feedback is important to us.
       </message>