[Offline indicator v2] Fix tablet CCT toolbar margin

Currently, top margin for the control container is calculated using
top_controls_height - tab_strip_and_toolbar_height (dimen). On tablet
CCTs, this may be negative since the tablet CCTs don't have a tab strip
while the tab_strip_and_toolbar_height always includes the tab strip
height on tablets.

A better way is to use the real view heights instead of dimens.

Bug: 1098716
Change-Id: I7428536b722df4489028115511a0c743665fd964
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2265176Reviewed-by: Theresa  <twellington@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Sinan Sahin <sinansahin@google.com>
Cr-Commit-Position: refs/heads/master@{#782656}

chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarManager.java

@@ -1123,9 +1123,14 @@ public class ToolbarManager implements UrlFocusChangeListener, ThemeColorObserve
      * @return The extra Y offset for the toolbar in pixels.
      */
     private int getToolbarExtraYOffset() {
-        final int stripAndToolbarHeight = mActivity.getResources().getDimensionPixelSize(
-                R.dimen.tab_strip_and_toolbar_height);
-        return mBrowserControlsSizer.getTopControlsHeight() - stripAndToolbarHeight;
+        return mBrowserControlsSizer.getTopControlsHeight()
+                - getControlContainerHeightWithoutShadow();
+    }
+
+    private int getControlContainerHeightWithoutShadow() {
+        final View toolbarShadow = mControlContainer.findViewById(R.id.toolbar_shadow);
+        final int shadowHeight = toolbarShadow != null ? toolbarShadow.getHeight() : 0;
+        return mControlContainer.getHeight() - shadowHeight;
     }
 
     /**