Tidy PDFWebContentsHelper members.

- Remove redundant |web_contents_|.
- Initialize them in the header when possible.
- Mark them const when possible.

Change-Id: Id7d709c128762e69e56b729a59e5481aaa8b44e1
Reviewed-on: https://chromium-review.googlesource.com/c/1339464Reviewed-by: Tommy Li <tommycli@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608825}

components/pdf/browser/pdf_web_contents_helper.cc

@@ -34,13 +34,7 @@ PDFWebContentsHelper::PDFWebContentsHelper(
     std::unique_ptr<PDFWebContentsHelperClient> client)
     : content::WebContentsObserver(web_contents),
       pdf_service_bindings_(web_contents, this),
-      client_(std::move(client)),
-      touch_selection_controller_client_manager_(nullptr),
-      selection_left_height_(0),
-      selection_right_height_(0),
-      has_selection_(false),
-      remote_pdf_client_(nullptr),
-      web_contents_(web_contents) {}
+      client_(std::move(client)) {}
 
 PDFWebContentsHelper::~PDFWebContentsHelper() {
   if (!touch_selection_controller_client_manager_)
@@ -58,7 +52,7 @@ gfx::PointF PDFWebContentsHelper::ConvertHelper(const gfx::PointF& point_f,
                                                 float scale) const {
   gfx::PointF origin_f;
   content::RenderWidgetHostView* view =
-      web_contents_->GetRenderWidgetHostView();
+      web_contents()->GetRenderWidgetHostView();
   if (view) {
     origin_f = view->TransformPointToRootCoordSpaceF(gfx::PointF());
     origin_f.Scale(scale);

components/pdf/browser/pdf_web_contents_helper.h

@@ -85,20 +85,18 @@ class PDFWebContentsHelper
                         int32_t right_height) override;
 
   content::WebContentsFrameBindingSet<mojom::PdfService> pdf_service_bindings_;
-  std::unique_ptr<PDFWebContentsHelperClient> client_;
+  std::unique_ptr<PDFWebContentsHelperClient> const client_;
   content::TouchSelectionControllerClientManager*
-      touch_selection_controller_client_manager_;
+      touch_selection_controller_client_manager_ = nullptr;
 
   // Latest selection bounds received from PDFium.
   gfx::PointF selection_left_;
-  int32_t selection_left_height_;
+  int32_t selection_left_height_ = 0;
   gfx::PointF selection_right_;
-  int32_t selection_right_height_;
-  bool has_selection_;
+  int32_t selection_right_height_ = 0;
+  bool has_selection_ = false;
 
   mojom::PdfListenerPtr remote_pdf_client_;
-  // Not owned.
-  content::WebContents* web_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(PDFWebContentsHelper);
 };