Implement HiDPI support in Pepper dev interface

This patch requires WebKit patch https://bugs.webkit.org/show_bug.cgi?id=87874 (WebKit r121364)

Expose device_scale_factor and css_scale_factor to Pepper plugins via a dev
interface on View resource.
Allow Pepper plugins to create a 2D graphics context with a scale factor so the
plugins can render at device resolution rather than DIPs if they want.

BUG=114673
TEST=browser_tests --gtest_filter="PPAPITest.*" 
TEST=browser_tests --gtest_filter="OutOfProcessPPAPITest.*"
TEST=Build, run existing PPAPI plugin at 2x scale
TEST=Build, run test HiDPI aware plugin to render at device rez, at 1x, 2x scale

Review URL: https://chromiumcodereview.appspot.com/10544168

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@144773 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 37 insertions, 1 deletions

diff --git a/ppapi/proxy/interface_list.cc b/ppapi/proxy/interface_list.cc
index f801276..ffed09f 100644
--- a/ppapi/proxy/interface_list.cc
+++ b/ppapi/proxy/interface_list.cc
@@ -15,6 +15,7 @@
 #include "ppapi/c/dev/ppb_font_dev.h"
 #include "ppapi/c/dev/ppb_fullscreen_dev.h"
 #include "ppapi/c/dev/ppb_gles_chromium_texture_mapping_dev.h"
+#include "ppapi/c/dev/ppb_graphics_2d_dev.h"
 #include "ppapi/c/dev/ppb_ime_input_event_dev.h"
 #include "ppapi/c/dev/ppb_keyboard_input_event_dev.h"
 #include "ppapi/c/dev/ppb_memory_dev.h"
@@ -27,6 +28,7 @@
 #include "ppapi/c/dev/ppb_url_util_dev.h"
 #include "ppapi/c/dev/ppb_var_deprecated.h"
 #include "ppapi/c/dev/ppb_video_capture_dev.h"
+#include "ppapi/c/dev/ppb_view_dev.h"
 #include "ppapi/c/ppb_audio_config.h"
 #include "ppapi/c/ppb_audio.h"
 #include "ppapi/c/ppb_core.h"
diff --git a/ppapi/proxy/ppapi_messages.h b/ppapi/proxy/ppapi_messages.h
index 69005e5..755d353 100644
--- a/ppapi/proxy/ppapi_messages.h
+++ b/ppapi/proxy/ppapi_messages.h
@@ -144,6 +144,8 @@ IPC_STRUCT_TRAITS_BEGIN(ppapi::ViewData)
   IPC_STRUCT_TRAITS_MEMBER(is_fullscreen)
   IPC_STRUCT_TRAITS_MEMBER(is_page_visible)
   IPC_STRUCT_TRAITS_MEMBER(clip_rect)
+  IPC_STRUCT_TRAITS_MEMBER(device_scale)
+  IPC_STRUCT_TRAITS_MEMBER(css_scale)
 IPC_STRUCT_TRAITS_END()
 
 IPC_STRUCT_TRAITS_BEGIN(PP_TouchPoint)
@@ -858,6 +860,9 @@ IPC_MESSAGE_ROUTED2(PpapiHostMsg_PPBGraphics2D_ReplaceContents,
                     ppapi::HostResource /* image_data */)
 IPC_MESSAGE_ROUTED1(PpapiHostMsg_PPBGraphics2D_Flush,
                     ppapi::HostResource /* graphics_2d */)
+IPC_MESSAGE_ROUTED2(PpapiHostMsg_PPBGraphics2D_Dev_SetScale,
+                    ppapi::HostResource /* graphics_2d */,
+                    float /* scale */)
 
 #if !defined(OS_NACL)
 // PPB_Graphics3D.
diff --git a/ppapi/proxy/ppb_graphics_2d_proxy.cc b/ppapi/proxy/ppb_graphics_2d_proxy.cc
index 2fc34cc..909abc1 100644
--- a/ppapi/proxy/ppb_graphics_2d_proxy.cc
+++ b/ppapi/proxy/ppb_graphics_2d_proxy.cc
@@ -43,6 +43,8 @@ class Graphics2D : public Resource, public thunk::PPB_Graphics2D_API {
   void Scroll(const PP_Rect* clip_rect,
               const PP_Point* amount);
   void ReplaceContents(PP_Resource image_data);
+  bool SetScale(float scale);
+  float GetScale();
   int32_t Flush(scoped_refptr<TrackedCallback> callback);
 
   // Notification that the host has sent an ACK for a pending Flush.
@@ -57,6 +59,7 @@ class Graphics2D : public Resource, public thunk::PPB_Graphics2D_API {
 
   PP_Size size_;
   PP_Bool is_always_opaque_;
+  float scale_;
 
   // In the plugin, this is the current callback set for Flushes. When the
   // pointer is non-NULL, we're waiting for a flush ACK.
@@ -70,7 +73,8 @@ Graphics2D::Graphics2D(const HostResource& host_resource,
                        PP_Bool is_always_opaque)
     : Resource(OBJECT_IS_PROXY, host_resource),
       size_(size),
-      is_always_opaque_(is_always_opaque) {
+      is_always_opaque_(is_always_opaque),
+      scale_(1.0f) {
 }
 
 Graphics2D::~Graphics2D() {
@@ -126,6 +130,19 @@ void Graphics2D::ReplaceContents(PP_Resource image_data) {
       kApiID, host_resource(), image_object->host_resource()));
 }
 
+bool Graphics2D::SetScale(float scale) {
+  if (scale <= 0.0f)
+    return false;
+  GetDispatcher()->Send(new PpapiHostMsg_PPBGraphics2D_Dev_SetScale(
+      kApiID, host_resource(), scale));
+  scale_ = scale;
+  return true;
+}
+
+float Graphics2D::GetScale() {
+  return scale_;
+}
+
 int32_t Graphics2D::Flush(scoped_refptr<TrackedCallback> callback) {
   if (TrackedCallback::IsPending(current_flush_callback_))
     return PP_ERROR_INPROGRESS;  // Can't have >1 flush pending.
@@ -178,6 +195,8 @@ bool PPB_Graphics2D_Proxy::OnMessageReceived(const IPC::Message& msg) {
                         OnHostMsgReplaceContents)
     IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBGraphics2D_Flush,
                         OnHostMsgFlush)
+    IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBGraphics2D_Dev_SetScale,
+                        OnHostMsgSetScale)
 
     IPC_MESSAGE_HANDLER(PpapiMsg_PPBGraphics2D_FlushACK,
                         OnPluginMsgFlushACK)
@@ -239,6 +258,14 @@ void PPB_Graphics2D_Proxy::OnHostMsgFlush(const HostResource& graphics_2d) {
   enter.SetResult(enter.object()->Flush(enter.callback()));
 }
 
+void PPB_Graphics2D_Proxy::OnHostMsgSetScale(const HostResource& graphics_2d,
+                                             float scale) {
+  EnterHostFromHostResource<PPB_Graphics2D_API> enter(graphics_2d);
+  if (enter.failed())
+    return;
+  enter.object()->SetScale(scale);
+}
+
 void PPB_Graphics2D_Proxy::OnPluginMsgFlushACK(
     const HostResource& host_resource,
     int32_t pp_error) {
diff --git a/ppapi/proxy/ppb_graphics_2d_proxy.h b/ppapi/proxy/ppb_graphics_2d_proxy.h
index f7afb64..45043ce 100644
--- a/ppapi/proxy/ppb_graphics_2d_proxy.h
+++ b/ppapi/proxy/ppb_graphics_2d_proxy.h
@@ -55,6 +55,8 @@ class PPB_Graphics2D_Proxy : public InterfaceProxy {
   void OnHostMsgReplaceContents(const HostResource& graphics_2d,
                                 const HostResource& image_data);
   void OnHostMsgFlush(const HostResource& graphics_2d);
+  void OnHostMsgSetScale(const HostResource& graphics_2d,
+                         float scale);
 
   // Host->plugin message handlers.
   void OnPluginMsgFlushACK(const HostResource& graphics_2d,