Adding diagnostic logging.

Bug=712331

Change-Id: I2ca492c7856546280bca9f1fc7da7a0837866495
Reviewed-on: https://chromium-review.googlesource.com/575702
Commit-Queue: Vadim Tryshev <vadimt@chromium.org>
Reviewed-by: Yury Khmel <khmel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487636}

chrome/browser/ui/app_list/search/answer_card/answer_card_search_provider.cc

@@ -34,6 +34,9 @@ enum class SearchAnswerRequestResult {
   REQUEST_RESULT_MAX = 5
 };
 
+constexpr char kSearchAnswerHasResult[] = "SearchAnswer-HasResult";
+constexpr char kSearchAnswerOpenResultUrl[] = "SearchAnswer-OpenResultUrl";
+
 void RecordRequestResult(SearchAnswerRequestResult request_result) {
   UMA_HISTOGRAM_ENUMERATION("SearchAnswer.RequestResult", request_result,
                             SearchAnswerRequestResult::REQUEST_RESULT_MAX);
@@ -133,13 +136,21 @@ content::WebContents* AnswerCardSearchProvider::OpenURLFromTab(
 void AnswerCardSearchProvider::DidFinishNavigation(
     content::NavigationHandle* navigation_handle) {
   if (navigation_handle->GetURL() != current_request_url_) {
+    // TODO(vadimt): Remove this and similar logging once testing is complete if
+    // we think this is not useful after release or happens too frequently.
+    VLOG(1) << "DidFinishNavigation: Another request started";
     RecordRequestResult(
         SearchAnswerRequestResult::REQUEST_RESULT_ANOTHER_REQUEST_STARTED);
     return;
   }
 
+  VLOG(1) << "DidFinishNavigation: Latest request completed";
   if (!navigation_handle->HasCommitted() || navigation_handle->IsErrorPage() ||
       !navigation_handle->IsInMainFrame()) {
+    LOG(ERROR) << "Failed to navigate: HasCommitted="
+               << navigation_handle->HasCommitted()
+               << ", IsErrorPage=" << navigation_handle->IsErrorPage()
+               << ", IsInMainFrame=" << navigation_handle->IsInMainFrame();
     RecordRequestResult(
         SearchAnswerRequestResult::REQUEST_RESULT_REQUEST_FAILED);
     return;
@@ -180,8 +191,14 @@ bool AnswerCardSearchProvider::IsCardSizeOk() const {
   if (features::IsAnswerCardDarkRunEnabled())
     return true;
 
-  return preferred_size_.width() <= features::AnswerCardMaxWidth() &&
-         preferred_size_.height() <= features::AnswerCardMaxHeight();
+  if (preferred_size_.width() <= features::AnswerCardMaxWidth() &&
+      preferred_size_.height() <= features::AnswerCardMaxHeight()) {
+    return true;
+  }
+
+  LOG(ERROR) << "Card is too large: width=" << preferred_size_.width()
+             << ", height=" << preferred_size_.height();
+  return false;
 }
 
 void AnswerCardSearchProvider::RecordReceivedAnswerFinalResult() {
@@ -211,14 +228,30 @@ void AnswerCardSearchProvider::OnResultAvailable(bool is_available) {
 
 bool AnswerCardSearchProvider::ParseResponseHeaders(
     const net::HttpResponseHeaders* headers) {
-  if (!headers || headers->response_code() != net::HTTP_OK)
+  if (!headers) {
+    LOG(ERROR) << "Failed to parse response headers: no headers";
+    return false;
+  }
+  if (headers->response_code() != net::HTTP_OK) {
+    LOG(ERROR) << "Failed to parse response headers: response code="
+               << headers->response_code();
     return false;
-  if (!headers->HasHeaderValue("SearchAnswer-HasResult", "true"))
+  }
+  if (!headers->HasHeaderValue(kSearchAnswerHasResult, "true")) {
+    VLOG(1) << "Failed to parse response headers: " << kSearchAnswerHasResult
+            << " header != true";
     return false;
-  if (!headers->GetNormalizedHeader("SearchAnswer-OpenResultUrl", &result_url_))
+  }
+  if (!headers->GetNormalizedHeader(kSearchAnswerOpenResultUrl, &result_url_)) {
+    LOG(ERROR) << "Failed to parse response headers: "
+               << kSearchAnswerOpenResultUrl << " header is not present";
     return false;
-  if (!headers->GetNormalizedHeader("SearchAnswer-Title", &result_title_))
+  }
+  if (!headers->GetNormalizedHeader("SearchAnswer-Title", &result_title_)) {
+    LOG(ERROR) << "Failed to parse response headers: SearchAnswer-Title header "
+                  "is not present";
     return false;
+  }
   return true;
 }