Create pp::Graphics2D in PaintManager::Client

Instead of directly creating and binding pp::Graphics2D in PaintManager,
delegate these operations to PaintManager::Client. This provides several
benefits:

1. Allows the PaintManager::Client to return a different pp::Graphics2D
   implementation in the future. This will be useful especially once we
   replace pp::Graphics2D with a Pepper-free API.
2. Eliminates the need for PaintManager to interact with pp::Instance.

Bug: 1099020
Change-Id: I46ce18cfb3ced088afdf6581fc335aa56b8be195
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2303989
Commit-Queue: K. Moon <kmoon@chromium.org>
Reviewed-by: Daniel Hosseinian <dhoss@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#789565}

pdf/out_of_process_instance.cc

@@ -40,6 +40,7 @@
 #include "ppapi/cpp/dev/memory_dev.h"
 #include "ppapi/cpp/dev/text_input_dev.h"
 #include "ppapi/cpp/dev/url_util_dev.h"
+#include "ppapi/cpp/graphics_2d.h"
 #include "ppapi/cpp/image_data.h"
 #include "ppapi/cpp/input_event.h"
 #include "ppapi/cpp/module.h"
@@ -47,6 +48,7 @@
 #include "ppapi/cpp/private/pdf.h"
 #include "ppapi/cpp/rect.h"
 #include "ppapi/cpp/resource.h"
+#include "ppapi/cpp/size.h"
 #include "ppapi/cpp/url_request_info.h"
 #include "ppapi/cpp/var_array.h"
 #include "ppapi/cpp/var_array_buffer.h"
@@ -446,7 +448,7 @@ OutOfProcessInstance::OutOfProcessInstance(PP_Instance instance)
     : pp::Instance(instance),
       pp::Find_Private(this),
       pp::Printing_Dev(this),
-      paint_manager_(this, this) {
+      paint_manager_(this) {
   callback_factory_.Initialize(this);
   pp::Module::Get()->AddPluginInterface(kPPPPdfInterface, &ppp_private);
   AddPerInstanceObject(kPPPPdfInterface, this);
@@ -948,6 +950,14 @@ void OutOfProcessInstance::StopFind() {
   SetTickmarks(tickmarks_);
 }
 
+pp::Graphics2D OutOfProcessInstance::CreatePaintGraphics(const pp::Size& size) {
+  return pp::Graphics2D(this, size, /*is_always_opaque=*/true);
+}
+
+bool OutOfProcessInstance::BindPaintGraphics(pp::Graphics2D& graphics) {
+  return BindGraphics(graphics);
+}
+
 void OutOfProcessInstance::OnPaint(const std::vector<pp::Rect>& paint_rects,
                                    std::vector<PaintReadyRect>* ready,
                                    std::vector<pp::Rect>* pending) {

pdf/out_of_process_instance.h

@@ -30,6 +30,8 @@
 #include "third_party/skia/include/core/SkBitmap.h"
 
 namespace pp {
+class Graphics2D;
+class Size;
 class TextInput_Dev;
 }
 
@@ -60,6 +62,8 @@ class OutOfProcessInstance : public pp::Instance,
   void StopFind() override;
 
   // pp::PaintManager::Client implementation.
+  pp::Graphics2D CreatePaintGraphics(const pp::Size& size) override;
+  bool BindPaintGraphics(pp::Graphics2D& graphics) override;
   void OnPaint(const std::vector<pp::Rect>& paint_rects,
                std::vector<PaintReadyRect>* ready,
                std::vector<pp::Rect>* pending) override;

pdf/paint_manager.cc

@@ -13,14 +13,11 @@
 #include "base/check_op.h"
 #include "pdf/paint_ready_rect.h"
 #include "ppapi/c/pp_errors.h"
-#include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/module.h"
 
 namespace chrome_pdf {
 
-PaintManager::PaintManager(pp::Instance* instance, Client* client)
-    : instance_(instance), client_(client) {
-  DCHECK(instance_);
+PaintManager::PaintManager(Client* client) : client_(client) {
   DCHECK(client_);
 
   // Set the callback object outside of the initializer list to avoid a
@@ -184,8 +181,7 @@ void PaintManager::DoPaint() {
     // we only resize by a small amount.
     pp::Size new_size = GetNewContextSize(graphics_.size(), pending_size_);
     if (graphics_.size() != new_size) {
-      graphics_ =
-          pp::Graphics2D(instance_, new_size, /*is_always_opaque=*/true);
+      graphics_ = client_->CreatePaintGraphics(new_size);
       graphics_need_to_be_bound_ = true;
 
       // Since we're binding a new one, all of the callbacks have been canceled.
@@ -258,7 +254,7 @@ void PaintManager::DoPaint() {
   first_paint_ = false;
 
   if (graphics_need_to_be_bound_) {
-    instance_->BindGraphics(graphics_);
+    client_->BindPaintGraphics(graphics_);
     graphics_need_to_be_bound_ = false;
   }
 }

pdf/paint_manager.h

@@ -14,9 +14,9 @@
 #include "ppapi/utility/completion_callback_factory.h"
 
 namespace pp {
-class Instance;
 class Point;
 class Rect;
+class Size;
 }  // namespace pp
 
 namespace chrome_pdf {
@@ -32,6 +32,14 @@ class PaintManager {
  public:
   class Client {
    public:
+    // Creates a new, unbound `pp::Graphics2D` for the paint manager, with the
+    // given |size| and always-opaque rendering.
+    virtual pp::Graphics2D CreatePaintGraphics(const pp::Size& size) = 0;
+
+    // Binds a `pp::Graphics2D` created by `CreatePaintGraphics()`, returning
+    // `true` if binding was successful.
+    virtual bool BindPaintGraphics(pp::Graphics2D& graphics) = 0;
+
     // Paints the given invalid area of the plugin to the given graphics
     // device. Returns true if anything was painted.
     //
@@ -56,20 +64,15 @@ class PaintManager {
 
    protected:
     // You shouldn't be doing deleting through this interface.
-    virtual ~Client() {}
+    ~Client() = default;
   };
 
-  // The instance is the plugin instance using this paint manager to do its
-  // painting. Painting will automatically go to this instance and you don't
-  // have to manually bind any device context (this is all handled by the
-  // paint manager).
-  //
   // The Client is a non-owning pointer and must remain valid (normally the
   // object implementing the Client interface will own the paint manager).
   //
   // You will need to call SetSize before this class will do anything. Normally
   // you do this from the ViewChanged method of your plugin instance.
-  PaintManager(pp::Instance* instance, Client* client);
+  explicit PaintManager(Client* client);
   PaintManager(const PaintManager&) = delete;
   PaintManager& operator=(const PaintManager&) = delete;
   ~PaintManager();
@@ -140,8 +143,6 @@ class PaintManager {
   // pending.
   void OnManualCallbackComplete(int32_t);
 
-  pp::Instance* const instance_;
-
   // Non-owning pointer. See the constructor.
   Client* const client_;