Android: Do not use TabImpl.getActivity in ToolbarButtonIPHController

ToolbarButtonIPHController is build with a particular ChromeActivity
and the objects associated with it. Therefore it doesn't need to
use TabImpl.getActivity() to get the current activity dynamically.
This CL removes replaces the use of API with the controller's
|mActivity|.

Bug: 952703
Change-Id: Ie3e601250192832f4fb2706e44e673c374a0129a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2129374Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Jinsuk Kim <jinsukkim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755155}

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

@@ -22,7 +22,6 @@ import org.chromium.chrome.browser.offlinepages.OfflinePageBridge;
 import org.chromium.chrome.browser.previews.Previews;
 import org.chromium.chrome.browser.profiles.Profile;
 import org.chromium.chrome.browser.tab.Tab;
-import org.chromium.chrome.browser.tab.TabImpl;
 import org.chromium.chrome.browser.toolbar.bottom.BottomToolbarConfiguration;
 import org.chromium.chrome.browser.translate.TranslateBridge;
 import org.chromium.chrome.browser.translate.TranslateUtils;
@@ -264,9 +263,8 @@ public class ToolbarButtonInProductHelpController
      */
     private void showDownloadPageTextBubble(final Tab tab, String featureName) {
         if (tab == null) return;
-        ChromeActivity activity = ((TabImpl) tab).getActivity();
-        if (!(activity instanceof ChromeTabbedActivity) || activity.isTablet()
-                || activity.isInOverviewMode() || !DownloadUtils.isAllowedToDownloadPage(tab)) {
+        if (!(mActivity instanceof ChromeTabbedActivity) || mActivity.isTablet()
+                || mActivity.isInOverviewMode() || !DownloadUtils.isAllowedToDownloadPage(tab)) {
             return;
         }
 
@@ -280,9 +278,7 @@ public class ToolbarButtonInProductHelpController
                         .setAnchorView(mActivity.getToolbarManager().getMenuButtonView())
                         .build());
         // Record metrics if we show Download IPH after a screenshot of the page.
-        ChromeTabbedActivity chromeActivity = ((ChromeTabbedActivity) activity);
-        ScreenshotTabObserver tabObserver =
-                ScreenshotTabObserver.from(chromeActivity.getActivityTab());
+        ScreenshotTabObserver tabObserver = ScreenshotTabObserver.from(tab);
         if (tabObserver != null) {
             tabObserver.onActionPerformedAfterScreenshot(
                     ScreenshotTabObserver.SCREENSHOT_ACTION_DOWNLOAD_IPH);