Port PepperGraphics2DHost to shared images

Bug: 945009
Change-Id: Iac5a5b59dfc5100e8c47a1c46ec9c586eacfe88c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1536347Reviewed-by: danakj <danakj@chromium.org>
Commit-Queue: Antoine Labour <piman@chromium.org>
Auto-Submit: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#644830}

content/renderer/pepper/pepper_graphics_2d_host.h

@@ -16,6 +16,7 @@
 #include "cc/resources/shared_bitmap_id_registrar.h"
 #include "content/common/content_export.h"
 #include "gpu/command_buffer/common/mailbox.h"
+#include "gpu/command_buffer/common/sync_token.h"
 #include "ppapi/c/ppb_graphics_2d.h"
 #include "ppapi/host/host_message_context.h"
 #include "ppapi/host/resource_host.h"
@@ -31,10 +32,6 @@ namespace gfx {
 class Rect;
 }
 
-namespace gpu {
-struct SyncToken;
-}
-
 namespace viz {
 class ContextProvider;
 class SingleReleaseCallback;
@@ -189,7 +186,8 @@ class CONTENT_EXPORT PepperGraphics2DHost
   static void ReleaseTextureCallback(
       base::WeakPtr<PepperGraphics2DHost> host,
       scoped_refptr<viz::ContextProvider> context,
-      uint32_t id,
+      const gfx::Size& size,
+      const gpu::Mailbox& mailbox,
       const gpu::SyncToken& sync_token,
       bool lost);
 
@@ -237,19 +235,17 @@ class CONTENT_EXPORT PepperGraphics2DHost
   // The shared main thread context provider, used to upload 2d pepper frames
   // if the compositor is expecting gpu content.
   scoped_refptr<viz::ContextProvider> main_thread_context_;
-  struct TextureInfo {
-    uint32_t id;
+  struct SharedImageInfo {
+    SharedImageInfo(gpu::SyncToken sync_token,
+                    gpu::Mailbox mailbox,
+                    gfx::Size size)
+        : sync_token(sync_token), mailbox(mailbox), size(size) {}
+    gpu::SyncToken sync_token;
     gpu::Mailbox mailbox;
     gfx::Size size;
   };
-  // The ids of textures holding the copied contents of software frames to
-  // give to the compositor via GL. Textures in this list are in use by the
-  // compositor and are treated as owned by the compositor until the
-  // ReleaseTextureCallback() informs otherwise.
-  std::vector<TextureInfo> texture_copies_;
-  // Texture ids move from |texture_copies_| to here once they are available for
-  // reuse.
-  std::vector<TextureInfo> recycled_texture_copies_;
+  // Shared images that are available for recycling.
+  std::vector<SharedImageInfo> recycled_shared_images_;
 
   // This is a bitmap that was recently released by the compositor and may be
   // used to transfer bytes to the compositor again, along with the registration