Enforce constant size and device scale factor for surfaces

android_webview/browser/hardware_renderer.cc

Index: android_webview/browser/hardware_renderer.cc
diff --git a/android_webview/browser/hardware_renderer.cc b/android_webview/browser/hardware_renderer.cc
index b51a383ecf3ed906ce83896ce9b25cecb1bfbb2b..f4962320364f7e100cf32147643c1a17686cef0f 100644
--- a/android_webview/browser/hardware_renderer.cc
+++ b/android_webview/browser/hardware_renderer.cc
@@ -118,18 +118,22 @@ void HardwareRenderer::DrawGL(AwDrawGLInfo* draw_info) {
     std::unique_ptr<cc::CompositorFrame> child_compositor_frame =
         std::move(child_frame_->frame);
 
+    float device_scale_factor =
+        child_compositor_frame->metadata.device_scale_factor;
     gfx::Size frame_size =
         child_compositor_frame->render_pass_list.back()->output_rect.size();
-    bool size_changed = frame_size != frame_size_;
-    frame_size_ = frame_size;
-    if (!child_id_.is_valid() || size_changed) {
+    if (!child_id_.is_valid() || surface_size_ != frame_size ||
+        device_scale_factor_ != device_scale_factor) {
       if (child_id_.is_valid())
         DestroySurface();
       AllocateSurface();
+      surface_size_ = frame_size;
+      device_scale_factor_ = device_scale_factor;
     }
 
-    support_->SubmitCompositorFrame(child_id_,
-                                    std::move(*child_compositor_frame));
+    bool result = support_->SubmitCompositorFrame(
+        child_id_, std::move(*child_compositor_frame));
+    DCHECK(result);
   }
 
   gfx::Transform transform(gfx::Transform::kSkipInitialization);
@@ -153,7 +157,7 @@ void HardwareRenderer::DrawGL(AwDrawGLInfo* draw_info) {
   gfx::Rect clip(draw_info->clip_left, draw_info->clip_top,
                  draw_info->clip_right - draw_info->clip_left,
                  draw_info->clip_bottom - draw_info->clip_top);
-  surfaces_->DrawAndSwap(viewport, clip, transform, frame_size_,
+  surfaces_->DrawAndSwap(viewport, clip, transform, surface_size_,
                          cc::SurfaceId(frame_sink_id_, child_id_));
 }
 
@@ -167,7 +171,7 @@ void HardwareRenderer::DestroySurface() {
   DCHECK(child_id_.is_valid());
 
   // Submit an empty frame to force any existing resources to be returned.
-  gfx::Rect rect(frame_size_);
+  gfx::Rect rect(surface_size_);
   std::unique_ptr<cc::RenderPass> render_pass = cc::RenderPass::Create();
   render_pass->SetNew(1, rect, rect, gfx::Transform());
   cc::CompositorFrame frame;
@@ -175,7 +179,9 @@ void HardwareRenderer::DestroySurface() {
   // We submit without a prior BeginFrame, so acknowledge a manual BeginFrame.
   frame.metadata.begin_frame_ack =
       cc::BeginFrameAck::CreateManualAckWithDamage();
-  support_->SubmitCompositorFrame(child_id_, std::move(frame));
+  frame.metadata.device_scale_factor = device_scale_factor_;
+  bool result = support_->SubmitCompositorFrame(child_id_, std::move(frame));
+  DCHECK(result);
 
   surfaces_->RemoveChildId(cc::SurfaceId(frame_sink_id_, child_id_));
   support_->EvictCurrentSurface();