Don't silently drop find-in-page request when PDF has not yet loaded.

This CL tweaks so that PDFiumEngine::StartFind doesn't *silently* drop
the find-in-page request when the PDF has not loaded yet.  Instead,
after the CL, the find-in-page client will be notified that the search
has completed with 0 results.

Bug: 964364, 965254
Change-Id: Ib528d407d1be34179aca2f04a792c582925f90a6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1629709
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#665279}

chrome/browser/download/save_page_browsertest.cc

@@ -1035,8 +1035,7 @@ class SavePageOriginalVsSavedComparisonTest
       const GURL& url,
       int expected_number_of_frames_in_original_page,
       int expected_number_of_frames_in_mhtml_page,
-      const std::vector<std::string>& expected_substrings,
-      bool skip_find_in_page = false) {
+      const std::vector<std::string>& expected_substrings) {
     // Navigate to the test page and verify if test expectations
     // are met (this is mostly a sanity check - a failure to meet
     // expectations would probably mean that there is a test bug
@@ -1045,8 +1044,7 @@ class SavePageOriginalVsSavedComparisonTest
     DLOG(INFO) << "Verifying test expectations for original page... : "
                << GetCurrentTab(browser())->GetLastCommittedURL();
     AssertExpectationsAboutCurrentTab(
-        expected_number_of_frames_in_original_page, expected_substrings,
-        skip_find_in_page);
+        expected_number_of_frames_in_original_page, expected_substrings);
 
     // Save the page.
     base::FilePath full_file_name, dir;
@@ -1074,7 +1072,7 @@ class SavePageOriginalVsSavedComparisonTest
         expected_number_of_frames_in_mhtml_page :
         expected_number_of_frames_in_original_page;
     AssertExpectationsAboutCurrentTab(expected_number_of_frames_in_saved_page,
-                                      expected_substrings, skip_find_in_page);
+                                      expected_substrings);
 
     if (GetParam() == content::SAVE_PAGE_TYPE_AS_MHTML) {
       std::set<url::Origin> origins;
@@ -1091,7 +1089,7 @@ class SavePageOriginalVsSavedComparisonTest
     chrome::GoBack(browser(), WindowOpenDisposition::CURRENT_TAB);
     content::WaitForLoadStop(GetCurrentTab(browser()));
     AssertExpectationsAboutCurrentTab(expected_number_of_frames_in_saved_page,
-                                      expected_substrings, skip_find_in_page);
+                                      expected_substrings);
   }
 
   // Helper method to deduplicate some code across 2 tests.
@@ -1120,42 +1118,34 @@ class SavePageOriginalVsSavedComparisonTest
         "frames-nested2.htm: 6d23dc47-f283-4977-96ec-66bcf72301a4",
         "text-object.txt: ae52dd09-9746-4b7e-86a6-6ada5e2680c2",
         "svg: 0875fd06-131d-4708-95e1-861853c6b8dc",
+
+        // TODO(lukasza): Consider also verifying presence of "PDF test file"
+        // from <object data="pdf.pdf">.  This requires ensuring that the PDF is
+        // loaded before continuing with the test.
     };
 
     // TODO(lukasza): crbug.com/553478: Enable <object> testing of MHTML.
     if (save_page_type == content::SAVE_PAGE_TYPE_AS_MHTML)
       return;
 
-    // TODO(lukasza): https://crbug.com/965254: Re-enable find-in-page aspect of
-    // the test.
-    bool skip_find_in_page =
-        content::MimeHandlerViewMode::UsesCrossProcessFrame();
-
     TestOriginalVsSavedPage(save_page_type, url, expected_number_of_frames,
-                            expected_number_of_frames, expected_substrings,
-                            skip_find_in_page);
+                            expected_number_of_frames, expected_substrings);
   }
 
  private:
   void AssertExpectationsAboutCurrentTab(
       int expected_number_of_frames,
-      const std::vector<std::string>& expected_substrings,
-      bool skip_find_in_page) {
+      const std::vector<std::string>& expected_substrings) {
     int actual_number_of_frames = 0;
     GetCurrentTab(browser())->ForEachFrame(base::BindRepeating(
         &IncrementInteger, base::Unretained(&actual_number_of_frames)));
     EXPECT_EQ(expected_number_of_frames, actual_number_of_frames);
 
-    // TODO(lukasza): https://crbug.com/965254: Re-enable find-in-page aspect of
-    // the test.
-    if (skip_find_in_page)
-      return;
-
     for (const auto& expected_substring : expected_substrings) {
       int actual_number_of_matches = ui_test_utils::FindInPage(
           GetCurrentTab(browser()), base::UTF8ToUTF16(expected_substring),
-          true,  // |forward|
-          true,  // |case_sensitive|
+          true,   // |forward|
+          false,  // |case_sensitive|
           nullptr, nullptr);
 
       EXPECT_EQ(1, actual_number_of_matches)
@@ -1173,7 +1163,7 @@ class SavePageOriginalVsSavedComparisonTest
     for (const auto& forbidden_substring : forbidden_substrings) {
       int actual_number_of_matches = ui_test_utils::FindInPage(
           GetCurrentTab(browser()), base::UTF8ToUTF16(forbidden_substring),
-          true,  // |forward|
+          true,   // |forward|
           false,  // |case_sensitive|
           nullptr, nullptr);
       EXPECT_EQ(0, actual_number_of_matches)

pdf/pdfium/pdfium_engine.cc

@@ -1838,8 +1838,10 @@ void PDFiumEngine::StartFind(const std::string& text, bool case_sensitive) {
 
   // If StartFind() gets called before we have any page information (i.e.
   // before the first call to LoadDocument has happened). Handle this case.
-  if (pages_.empty())
+  if (pages_.empty()) {
+    client_->NotifyNumberOfFindResultsChanged(0, true);
     return;
+  }
 
   bool first_search = (current_find_text_ != text);
   int character_to_start_searching_from = 0;