Miscellaneous cleanup for Ephemeral tab

This CL adds
1 - Clean up the extra bottom padding on the toolbar layout, since
it is not required any more after defining custom height for PEEK state.
2 - Added accessibility strings for various height states

Bug: 1013461
Change-Id: I2d5fd47be139bba0ad9a584aff175e32f76f5e46
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1854795Reviewed-by: Matthew Jones <mdjones@chromium.org>
Reviewed-by: Jinsuk Kim <jinsukkim@chromium.org>
Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705348}

chrome/android/java/res/layout/ephemeral_tab_toolbar.xml

@@ -8,8 +8,7 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:layout_height="100dp"
-    android:paddingBottom="30dp">
+    android:layout_height="@dimen/preview_tab_toolbar_height">
 
     <LinearLayout
         android:id="@+id/toolbar"

chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/ephemeraltab/EphemeralTabSheetContent.java

@@ -215,24 +215,23 @@ public class EphemeralTabSheetContent implements BottomSheet.BottomSheetContent
         return 0.9f;
     }
 
-    // TODO(shaktisahu): Provide correct strings for the following methods.
     @Override
     public int getSheetContentDescriptionStringId() {
-        return R.string.send_tab_to_self_content_description;
+        return R.string.ephemeral_tab_sheet_description;
     }
 
     @Override
     public int getSheetHalfHeightAccessibilityStringId() {
-        return R.string.send_tab_to_self_sheet_half_height;
+        return R.string.ephemeral_tab_sheet_opened_half;
     }
 
     @Override
     public int getSheetFullHeightAccessibilityStringId() {
-        return R.string.send_tab_to_self_sheet_full_height;
+        return R.string.ephemeral_tab_sheet_opened_full;
     }
 
     @Override
     public int getSheetClosedAccessibilityStringId() {
-        return R.string.send_tab_to_self_sheet_closed;
+        return R.string.ephemeral_tab_sheet_closed;
     }
 }

chrome/android/java/strings/android_chrome_strings.grd

@@ -3357,6 +3357,20 @@ To change this setting, <ph name="BEGIN_LINK">&lt;resetlink&gt;</ph>reset sync<p
         Navigation history is closed
       </message>
 
+      <!-- Ephemeral Tab -->
+      <message name="IDS_EPHEMERAL_TAB_SHEET_DESCRIPTION" desc="The content description of the preview tab bottom sheet.">
+        Preview tab
+      </message>
+      <message name="IDS_EPHEMERAL_TAB_SHEET_OPENED_HALF" desc="Accessibility string read when the preview tab bottom sheet is opened at half height. The sheet will occupy up to half the screen.">
+        Preview tab is half-opened
+      </message>
+      <message name="IDS_EPHEMERAL_TAB_SHEET_OPENED_FULL" desc="Accessibility string read when the preview tab bottom sheet is opened at full height. The sheet will occupy up to the full screen.">
+        Preview tab is opened
+      </message>
+      <message name="IDS_EPHEMERAL_TAB_SHEET_CLOSED" desc="Accessibility string read when the preview tab bottom sheet is closed.">
+        Preview tab is closed
+      </message>
+
       <!-- Storage Preference UI strings for clearing storage. -->
       <message name="IDS_STORAGE_MANAGEMENT_ACTIVITY_LABEL" desc="Title for Chrome's Manage Space Activity.">
          Google <ph name="APP_NAME">%1$s<ex>Chrome</ex></ph> storage