Enforce constant size and device scale factor for surfaces

android_webview/browser/hardware_renderer.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "android_webview/browser/hardware_renderer.h"
 
 #include <utility>
 
 #include "android_webview/browser/aw_gl_surface.h"
 #include "android_webview/browser/aw_render_thread_context_provider.h"
@@ skipping 100 matching lines @@
 
       CreateNewCompositorFrameSinkSupport();
       compositor_id_ = child_frame_->compositor_id;
       last_submitted_compositor_frame_sink_id_ =
           child_frame_->compositor_frame_sink_id;
     }
 
     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));
   }
 
   gfx::Transform transform(gfx::Transform::kSkipInitialization);
   transform.matrix().setColMajorf(draw_info->transform);
   transform.Translate(scroll_offset_.x(), scroll_offset_.y());
 
   gfx::Size viewport(draw_info->width, draw_info->height);
   // Need to post the new transform matrix back to child compositor
   // because there is no onDraw during a Render Thread animation, and child
   // compositor might not have the tiles rasterized as the animation goes on.
   ParentCompositorDrawConstraints draw_constraints(
       draw_info->is_layer, transform, viewport.IsEmpty());
   if (!child_frame_.get() || draw_constraints.NeedUpdate(*child_frame_)) {
     render_thread_manager_->PostExternalDrawConstraintsToChildCompositorOnRT(
         draw_constraints);
   }
 
   if (!child_id_.is_valid())
     return;
 
   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_));
 }
 
 void HardwareRenderer::AllocateSurface() {
   DCHECK(!child_id_.is_valid());
   child_id_ = local_surface_id_allocator_->GenerateId();
   surfaces_->AddChildId(cc::SurfaceId(frame_sink_id_, child_id_));
 }
 
 void HardwareRenderer::DestroySurface() {
@@ skipping 90 matching lines @@
   constexpr bool is_root = false;
   constexpr bool handles_frame_sink_id_invalidation = false;
   constexpr bool needs_sync_points = true;
   support_.reset();
   support_ = cc::CompositorFrameSinkSupport::Create(
       this, surfaces_->GetSurfaceManager(), frame_sink_id_, is_root,
       handles_frame_sink_id_invalidation, needs_sync_points);
 }
 
 }  // namespace android_webview