Fix Find behaving like Find Next

This bug happened in two cases when using Find:
1) On macOS, always
2) On all platforms, when text is selected

This change fixes both cases, while also unifying macOS behavior with
other platforms. (I think the previous exclusion of macOS from the
find-from-selection behavior may have been due to a misunderstanding of
some mac-specific code/comments.)

Now, when doing a find-from-selection, the initial result is the same
selected text, rather than the next occurrence. So it's a no-op
(as it should be) in terms of the selection and the document scroll
position.

Bug: 1043550
Change-Id: I78a27b74324f74b1e3c7528fc91badf85f65d22f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2145247
Auto-Submit: Russell Davis <russell.davis@gmail.com>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Jeff Fisher <jeffish@microsoft.com>
Commit-Queue: Jeff Fisher <jeffish@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#759048}

AUTHORS

@@ -827,6 +827,7 @@ Ruben Bridgewater <ruben@bridgewater.de>
 Ruben Terrazas <rubentopo@gmail.com>
 Rufus Hamade <rufus.hamade@imgtec.com>
 Ruiyi Luo <luoruiyi2008@gmail.com>
+Russell Davis <russell.davis@gmail.com>
 Ryan Ackley <ryanackley@gmail.com>
 Ryan Norton <rnorton10@gmail.com>
 Ryan Sleevi <ryan-chromium-dev@sleevi.com>

chrome/browser/ui/find_bar/find_bar_controller.cc

@@ -51,27 +51,37 @@ void FindBarController::Show(bool find_next, bool forward_direction) {
   find_bar_->SetFocusAndSelection();
 
   base::string16 find_text;
-  if (!find_next && !has_user_modified_text_) {
-    base::string16 selected_text = GetSelectedText();
-    if (selected_text.length() <= 250)
-      find_text = selected_text;
-  }
 
 #if defined(OS_MACOSX)
-  // We always want to search for the current contents of the find bar on
-  // OS X. For regular profile it's always the current find pboard. For
-  // Incognito window it's the newest value of the find pboard content and
-  // user-typed text.
-  find_text = find_bar_->GetFindText();
+  if (find_next) {
+    // For macOS, we always want to search for the current contents of the find
+    // bar on OS X, rather than the behavior we'd get with empty find_text
+    // (see FindBarState::GetSearchPrepopulateText).
+    find_text = find_bar_->GetFindText();
+  }
 #endif
 
-  if (!find_text.empty() || find_next) {
-    // Don't update the local input if we're using the global pasteboard.
-    if (!find_bar_->HasGlobalFindPasteboard())
+  if (!find_next && !has_user_modified_text_) {
+    base::string16 selected_text = GetSelectedText();
+    auto selected_length = selected_text.length();
+    if (selected_length > 0 && selected_length <= 250) {
+      find_text = selected_text;
       find_bar_->SetFindTextAndSelectedRange(find_text,
                                              gfx::Range(0, find_text.length()));
-    find_tab_helper->StartFinding(find_text, forward_direction, false);
+      if (web_contents_) {
+        // Collapse the selection to its start, so we can run a find_next and
+        // make it find the selection. This is a no-op in terms of what ends
+        // up selected, but initializes the rest of the find machinery (like
+        // showing how many matches there are in the document).
+        web_contents_->AdjustSelectionByCharacterOffset(0, -selected_length,
+                                                        false);
+        find_next = true;
+      }
+    }
   }
+
+  if (find_next)
+    find_tab_helper->StartFinding(find_text, forward_direction, false);
 }
 
 void FindBarController::EndFindSession(

chrome/browser/ui/views/find_bar_views_interactive_uitest.cc

@@ -619,8 +619,6 @@ IN_PROC_BROWSER_TEST_F(FindInPageTest, MAYBE_CtrlEnter) {
   observer.Wait();
 }
 
-// FindInPage on Mac doesn't use prepopulated values. Search there is global.
-#if !defined(OS_MACOSX)
 IN_PROC_BROWSER_TEST_F(FindInPageTest, SelectionDuringFind) {
   ASSERT_TRUE(embedded_test_server()->Start());
   // Make sure Chrome is in the foreground, otherwise sending input
@@ -645,12 +643,14 @@ IN_PROC_BROWSER_TEST_F(FindInPageTest, SelectionDuringFind) {
   browser()->GetFindBarController()->Show();
   EXPECT_TRUE(IsViewFocused(browser(), VIEW_ID_FIND_IN_PAGE_TEXT_FIELD));
 
-  // verify the text matches the selection
+  // Verify the text matches the selection
   EXPECT_EQ(ASCIIToUTF16("text"), GetFindBarText());
   find_in_page::FindNotificationDetails details = WaitForFindResult();
-  EXPECT_TRUE(details.number_of_matches() > 0);
+  // Verify the correct match is highlighted (the one corresponding to the
+  // text that was selected). See http://crbug.com/1043550
+  EXPECT_EQ(2, details.active_match_ordinal());
+  EXPECT_EQ(5, details.number_of_matches());
 }
-#endif
 
 IN_PROC_BROWSER_TEST_F(FindInPageTest, GlobalEscapeClosesFind) {
   ASSERT_TRUE(embedded_test_server()->Start());