[unseasoned-pdf] Add unit tests for DocumentLoadComplete().

Add unit tests for PdfViewPluginBase::DocumentLoadComplete(), which
exercises multiple private methods: DidStopLoading(), SendAttachments(),
SendBookmarks(), SendMetadata(), SendLoadingProgress() and
LoadAccessibility().

Also make `AccessibilityState` and `kMaximumSavedFileSize` public so
that they can be used in unit tests.

Change-Id: I8d548dd1f2eb5f9e6d860b0d8f1e1fe4fb329389
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2986560
Commit-Queue: Hui Yingst <nigi@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#898413}

pdf/accessibility_structs.cc

@@ -6,6 +6,16 @@
 
 namespace chrome_pdf {
 
+bool AccessibilityDocInfo::operator==(const AccessibilityDocInfo& other) const {
+  return page_count == other.page_count &&
+         text_accessible == other.text_accessible &&
+         text_copyable == other.text_copyable;
+}
+
+bool AccessibilityDocInfo::operator!=(const AccessibilityDocInfo& other) const {
+  return !(*this == other);
+}
+
 AccessibilityTextStyleInfo::AccessibilityTextStyleInfo() = default;
 
 AccessibilityTextStyleInfo::AccessibilityTextStyleInfo(

pdf/accessibility_structs.h

@@ -17,6 +17,9 @@
 namespace chrome_pdf {
 
 struct AccessibilityDocInfo {
+  bool operator==(const AccessibilityDocInfo& other) const;
+  bool operator!=(const AccessibilityDocInfo& other) const;
+
   uint32_t page_count = 0;
   bool text_accessible = false;
   bool text_copyable = false;

pdf/pdf_view_plugin_base.h

@@ -61,6 +61,16 @@ class PdfViewPluginBase : public PDFEngine::Client,
  public:
   using PDFEngine::Client::ScheduleTaskOnMainThread;
 
+  // Do not save files with over 100 MB. This cap should be kept in sync with
+  // and is also enforced in chrome/browser/resources/pdf/pdf_viewer.js.
+  static constexpr size_t kMaximumSavedFileSize = 100 * 1000 * 1000;
+
+  enum class AccessibilityState {
+    kOff = 0,  // Off.
+    kPending,  // Enabled but waiting for doc to load.
+    kLoaded,   // Fully loaded.
+  };
+
   enum class DocumentLoadState {
     kLoading = 0,
     kComplete,
@@ -148,16 +158,6 @@ class PdfViewPluginBase : public PDFEngine::Client,
   }
 
  protected:
-  // Do not save files with over 100 MB. This cap should be kept in sync with
-  // and is also enforced in chrome/browser/resources/pdf/pdf_viewer.js.
-  static constexpr size_t kMaximumSavedFileSize = 100 * 1000 * 1000;
-
-  enum class AccessibilityState {
-    kOff = 0,  // Off.
-    kPending,  // Enabled but waiting for doc to load.
-    kLoaded,   // Fully loaded.
-  };
-
   struct BackgroundPart {
     gfx::Rect location;
     uint32_t color;