[Autofill Assistant] Added DVLOGs to web_controller.

To provide human-readable status messages, several enums now support the output operator <<. String representations of enums are only compiled into debug builds. The same is true for logging string representations of selectors, because they might contain sensitive data.

Bug: 806868
Change-Id: I09de68f93a612cd4060761e8171b0bcd959df942
Reviewed-on: https://chromium-review.googlesource.com/c/1455901
Commit-Queue: Clemens Arbesser <arbesser@google.com>
Reviewed-by: Stephane Zermatten <szermatt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630716}

components/autofill_assistant/browser/controller.cc

@@ -196,7 +196,7 @@ void Controller::EnterState(AutofillAssistantState state) {
     return;
 
   DCHECK_NE(state_, AutofillAssistantState::STOPPED)
-      << "Unexpected transition from STOPPED to " << static_cast<int>(state);
+      << "Unexpected transition from " << state_ << " to " << state;
 
   state_ = state;
   GetUiController()->OnStateChanged(state);
@@ -540,8 +540,8 @@ void Controller::GetTouchableArea(std::vector<RectF>* area) const {
 void Controller::OnFatalError(const std::string& error_message,
                               Metrics::DropOutReason reason) {
   LOG(ERROR) << "Autofill Assistant has encountered an error and is shutting "
-                "down. Reason: "
-             << static_cast<int>(reason);
+                "down, reason="
+             << reason;
   if (state_ == AutofillAssistantState::STOPPED)
     return;
 

components/autofill_assistant/browser/metrics.h

@@ -5,6 +5,8 @@
 #ifndef COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_METRICS_H_
 #define COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_METRICS_H_
 
+#include <ostream>
+
 namespace autofill_assistant {
 
 // A class to generate Autofill Assistant related histograms.
@@ -37,6 +39,76 @@ class Metrics {
   };
 
   static void RecordDropOut(DropOutReason reason);
+
+  // Intended for debugging: writes string representation of |reason| to |out|.
+  friend std::ostream& operator<<(std::ostream& out,
+                                  const DropOutReason& reason) {
+#ifdef NDEBUG
+    // Non-debugging builds write the enum number.
+    out << static_cast<int>(reason);
+    return out;
+#else
+    // Debugging builds write a string representation of |reason|.
+    switch (reason) {
+      case AA_START:
+        out << "AA_START";
+        break;
+      case AUTOSTART_TIMEOUT:
+        out << "AUTOSTART_TIMEOUT";
+        break;
+      case NO_SCRIPTS:
+        out << "NO_SCRIPTS";
+        break;
+      case CUSTOM_TAB_CLOSED:
+        out << "CUSTOM_TAB_CLOSED";
+        break;
+      case DECLINED:
+        out << "DECLINED";
+        break;
+      case SHEET_CLOSED:
+        out << "SHEET_CLOSED";
+        break;
+      case SCRIPT_FAILED:
+        out << "SCRIPT_FAILED";
+        break;
+      case NAVIGATION:
+        out << "NAVIGATION";
+        break;
+      case OVERLAY_STOP:
+        out << "OVERLAY_STOP";
+        break;
+      case PR_FAILED:
+        out << "PR_FAILED";
+        break;
+      case CONTENT_DESTROYED:
+        out << "CONTENT_DESTROYED";
+        break;
+      case RENDER_PROCESS_GONE:
+        out << "RENDER_PROCESS_GONE";
+        break;
+      case INTERSTITIAL_PAGE:
+        out << "INTERSTITIAL_PAGE";
+        break;
+      case SCRIPT_SHUTDOWN:
+        out << "SCRIPT_SHUTDOWN";
+        break;
+      case SAFETY_NET_TERMINATE:
+        out << "SAFETY_NET_TERMINATE";
+        break;
+      case TAB_DETACHED:
+        out << "TAB_DETACHED";
+        break;
+      case TAB_CHANGED:
+        out << "TAB_CHANGED";
+        break;
+      case NUM_ENTRIES:
+        out << "NUM_ENTRIES";
+        // Intentionally no default case to make compilation fail if a new value
+        // was added to the enum but not to this list.
+    }
+    return out;
+#endif  // NDEBUG
+  }
 };
 
 }  // namespace autofill_assistant

components/autofill_assistant/browser/selector.cc

@@ -4,6 +4,8 @@
 
 #include "components/autofill_assistant/browser/selector.h"
 
+#include "base/strings/string_util.h"
+
 namespace autofill_assistant {
 
 Selector::Selector() : pseudo_type(PseudoType::UNDEFINED) {}
@@ -41,4 +43,14 @@ bool Selector::empty() const {
   return this->selectors.empty();
 }
 
-}  // namespace autofill_assistant
+std::ostream& operator<<(std::ostream& out, const Selector& selector) {
\ No newline at end of file
+#ifdef NDEBUG
+  out << selector.selectors.size() << " element(s)";
+  return out;
+#else
+  out << "elements=[" << base::JoinString(selector.selectors, ",") << "]";
+  return out;
+#endif  // NDEBUG
+}
+
+}  // namespace autofill_assistant

components/autofill_assistant/browser/selector.h

@@ -5,6 +5,7 @@
 #ifndef COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_SELECTOR_H_
 #define COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_SELECTOR_H_
 
+#include <ostream>
 #include <string>
 #include <vector>
 
@@ -39,6 +40,10 @@ struct Selector {
   bool operator<(const Selector& other) const;
   bool operator==(const Selector& other) const;
 
+  // The output operator. The actual selectors are only available in debug
+  // builds.
+  friend std::ostream& operator<<(std::ostream& out, const Selector& selector);
+
   // Checks whether this selector is empty.
   bool empty() const;
 };

components/autofill_assistant/browser/state.h

@@ -5,6 +5,8 @@
 #ifndef COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_STATE_H_
 #define COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_STATE_H_
 
+#include <ostream>
+
 namespace autofill_assistant {
 
 // High-level states the Autofill Assistant can be in.
@@ -47,6 +49,43 @@ enum class AutofillAssistantState {
   STOPPED
 };
 
+inline std::ostream& operator<<(std::ostream& out,
+                                const AutofillAssistantState& state) {
+#ifdef NDEBUG
+  // Non-debugging builds write the enum number.
+  out << static_cast<int>(state);
+  return out;
+#else
+  // Debugging builds write a string representation of |state|.
+  switch (state) {
+    case AutofillAssistantState::INACTIVE:
+      out << "INACTIVE";
+      break;
+    case AutofillAssistantState::STARTING:
+      out << "STARTING";
+      break;
+    case AutofillAssistantState::RUNNING:
+      out << "RUNNING";
+      break;
+    case AutofillAssistantState::PROMPT:
+      out << "PROMPT";
+      break;
+    case AutofillAssistantState::AUTOSTART_FALLBACK_PROMPT:
+      out << "AUTOSTART_FALLBACK_PROMPT";
+      break;
+    case AutofillAssistantState::MODAL_DIALOG:
+      out << "MODAL_DIALOG";
+      break;
+    case AutofillAssistantState::STOPPED:
+      out << "STOPPED";
+      break;
+      // Intentionally no default case to make compilation fail if a new value
+      // was added to the enum but not to this list.
+  }
+  return out;
+#endif  // NDEBUG
+}
+
 }  // namespace autofill_assistant
 
 #endif  // COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_STATE_H_