Convert 0 to nullptr in content using clang-tidy.

Bug: 778942
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_site_isolation
Change-Id: Iee6be84c23149c745b3afd6e6158764f92ccd17f
Reviewed-on: https://chromium-review.googlesource.com/732305
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Ivan Kotenkov <kotenkov@yandex-team.ru>
Cr-Commit-Position: refs/heads/master@{#513138}

content/app/content_main_runner.cc

@@ -450,8 +450,8 @@ class ContentMainRunnerImpl : public ContentMainRunner {
       : is_initialized_(false),
         is_shutdown_(false),
         completed_basic_startup_(false),
-        delegate_(NULL),
-        ui_task_(NULL) {
+        delegate_(nullptr),
+        ui_task_(nullptr) {
 #if defined(OS_WIN)
     memset(&sandbox_info_, 0, sizeof(sandbox_info_));
 #endif
@@ -724,9 +724,9 @@ class ContentMainRunnerImpl : public ContentMainRunner {
 #endif  // _CRTDBG_MAP_ALLOC
 #endif  // OS_WIN
 
-    exit_manager_.reset(NULL);
+    exit_manager_.reset(nullptr);
 
-    delegate_ = NULL;
+    delegate_ = nullptr;
     is_shutdown_ = true;
   }
 

content/browser/accessibility/accessibility_ui.cc

@@ -102,7 +102,7 @@ std::unique_ptr<base::DictionaryValue> BuildTargetDescriptor(
     title = base::UTF16ToUTF8(web_contents->GetTitle());
     NavigationController& controller = web_contents->GetController();
     NavigationEntry* entry = controller.GetVisibleEntry();
-    if (entry != NULL && entry->GetURL().is_valid())
+    if (entry != nullptr && entry->GetURL().is_valid())
       favicon_url = entry->GetFavicon().url;
     accessibility_mode = web_contents->GetAccessibilityMode();
   }

content/browser/accessibility/browser_accessibility.cc

@@ -494,9 +494,9 @@ base::string16 BrowserAccessibility::GetValue() const {
 BrowserAccessibility* BrowserAccessibility::ApproximateHitTest(
     const gfx::Point& point) {
   // The best result found that's a child of this object.
-  BrowserAccessibility* child_result = NULL;
+  BrowserAccessibility* child_result = nullptr;
   // The best result that's an indirect descendant like grandchild, etc.
-  BrowserAccessibility* descendant_result = NULL;
+  BrowserAccessibility* descendant_result = nullptr;
 
   // Walk the children recursively looking for the BrowserAccessibility that
   // most tightly encloses the specified point. Walk backwards so that in
@@ -537,8 +537,8 @@ BrowserAccessibility* BrowserAccessibility::ApproximateHitTest(
 }
 
 void BrowserAccessibility::Destroy() {
-  node_ = NULL;
-  manager_ = NULL;
+  node_ = nullptr;
+  manager_ = nullptr;
 
   NativeReleaseReference();
 }