find_in_page: FindTabHelper need not be a WebContentsObserver.

It has not actually observed anything in over eight years, when it
stopped overriding TabContentsObserver::OnMessageReceived.
  https://codereview.chromium.org/7828025/diff/2005/chrome/browser/ui/find_bar/find_tab_helper.h

All it actually cares about is storing a WebContents*, which there are
simpler ways to do.

While here, remove two includes which no longer seem used.

Change-Id: Iabb87720cde91b5edf16a6039fe602cc2e6cb4ed
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2224028
Commit-Queue: Jeremy Roman <jbroman@chromium.org>
Auto-Submit: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774461}

components/find_in_page/find_tab_helper.cc

@@ -11,9 +11,7 @@
 #include "build/build_config.h"
 #include "components/find_in_page/find_result_observer.h"
 #include "components/find_in_page/find_types.h"
-#include "content/public/browser/notification_service.h"
 #include "content/public/browser/render_frame_host.h"
-#include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/stop_find_action.h"
 #include "third_party/blink/public/mojom/frame/find_in_page.mojom.h"
@@ -27,7 +25,7 @@ namespace find_in_page {
 int FindTabHelper::find_request_id_counter_ = -1;
 
 FindTabHelper::FindTabHelper(WebContents* web_contents)
-    : content::WebContentsObserver(web_contents),
+    : web_contents_(web_contents),
       current_find_request_id_(find_request_id_counter_++),
       current_find_session_id_(current_find_request_id_) {}
 
@@ -93,8 +91,7 @@ void FindTabHelper::StartFinding(base::string16 search_string,
   options->match_case = case_sensitive;
   options->find_next = find_next;
   options->run_synchronously_for_testing = run_synchronously_for_testing;
-  web_contents()->Find(current_find_request_id_, find_text_,
-                       std::move(options));
+  web_contents_->Find(current_find_request_id_, find_text_, std::move(options));
 }
 
 void FindTabHelper::StopFinding(SelectionAction selection_action) {
@@ -128,11 +125,11 @@ void FindTabHelper::StopFinding(SelectionAction selection_action) {
       NOTREACHED();
       action = content::STOP_FIND_ACTION_KEEP_SELECTION;
   }
-  web_contents()->StopFinding(action);
+  web_contents_->StopFinding(action);
 }
 
 void FindTabHelper::ActivateFindInPageResultForAccessibility() {
-  web_contents()->GetMainFrame()->ActivateFindInPageResultForAccessibility(
+  web_contents_->GetMainFrame()->ActivateFindInPageResultForAccessibility(
       current_find_request_id_);
 }
 
@@ -148,13 +145,13 @@ base::string16 FindTabHelper::GetInitialSearchText() {
 #if defined(OS_ANDROID)
 void FindTabHelper::ActivateNearestFindResult(float x, float y) {
   if (!find_op_aborted_ && !find_text_.empty()) {
-    web_contents()->ActivateNearestFindResult(x, y);
+    web_contents_->ActivateNearestFindResult(x, y);
   }
 }
 
 void FindTabHelper::RequestFindMatchRects(int current_version) {
   if (!find_op_aborted_ && !find_text_.empty())
-    web_contents()->RequestFindMatchRects(current_version);
+    web_contents_->RequestFindMatchRects(current_version);
 }
 #endif
 
@@ -184,7 +181,7 @@ void FindTabHelper::HandleFindReply(int request_id,
         FindNotificationDetails(request_id, number_of_matches, selection,
                                 active_match_ordinal, final_update);
     for (auto& observer : observers_)
-      observer.OnFindResultAvailable(web_contents());
+      observer.OnFindResultAvailable(web_contents_);
   }
 }
 

components/find_in_page/find_tab_helper.h

@@ -8,7 +8,6 @@
 #include "base/strings/string16.h"
 #include "build/build_config.h"
 #include "components/find_in_page/find_notification_details.h"
-#include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 #include "ui/gfx/range/range.h"
 
@@ -18,8 +17,7 @@ class FindResultObserver;
 enum class SelectionAction;
 
 // Per-tab find manager. Handles dealing with the life cycle of find sessions.
-class FindTabHelper : public content::WebContentsObserver,
-                      public content::WebContentsUserData<FindTabHelper> {
+class FindTabHelper : public content::WebContentsUserData<FindTabHelper> {
  public:
   // The delegate tracks search text state.
   class Delegate {
@@ -126,6 +124,9 @@ class FindTabHelper : public content::WebContentsObserver,
   // the user has issued a new search).
   static int find_request_id_counter_;
 
+  // The WebContents which owns this helper.
+  content::WebContents* web_contents_ = nullptr;
+
   // True if the Find UI is active for this Tab.
   bool find_ui_active_ = false;