Fix UpdateTilePriorities viewport in Android WebView.

cc/layers/picture_layer_impl.cc

 // Copyright 2012 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 "cc/layers/picture_layer_impl.h"
 
 #include <algorithm>
 
 #include "base/time/time.h"
 #include "cc/base/math_util.h"
@@ skipping 275 matching lines @@
 
   // Aggressively remove any tilings that are not seen to save memory. Note
   // that this is at the expense of doing cause more frequent re-painting. A
   // better scheme would be to maintain a tighter visible_content_rect for the
   // finer tilings.
   CleanUpTilingsOnActiveLayer(seen_tilings);
 }
 
 void PictureLayerImpl::UpdateTilePriorities() {
   DCHECK(!needs_post_commit_initialization_);
+  if (!layer_tree_impl()->device_viewport_valid_for_tile_management()) {
+    for (size_t i = 0; i < tilings_->num_tilings(); ++i)
+      DCHECK(tilings_->tiling_at(i)->has_ever_been_updated());
+    return;
+  }
+
   if (!tilings_->num_tilings())
     return;
 
   double current_frame_time_in_seconds =
       (layer_tree_impl()->CurrentFrameTimeTicks() -
        base::TimeTicks()).InSecondsF();
 
   bool tiling_needs_update = false;
   for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
     if (tilings_->tiling_at(i)->NeedsUpdateForFrameAtTime(
             current_frame_time_in_seconds)) {
       tiling_needs_update = true;
       break;
     }
   }
   if (!tiling_needs_update)
     return;
 
   // At this point, tile priorities are going to be modified.
   layer_tree_impl()->WillModifyTilePriorities();
 
   UpdateLCDTextStatus(can_use_lcd_text());
 
   gfx::Transform current_screen_space_transform = screen_space_transform();
 
+  gfx::Size viewport_size = layer_tree_impl()->DrawViewportSize();
   gfx::Rect viewport_in_content_space;
   gfx::Transform screen_to_layer(gfx::Transform::kSkipInitialization);
   if (screen_space_transform().GetInverse(&screen_to_layer)) {
-    gfx::Rect device_viewport(layer_tree_impl()->device_viewport_size());
-    viewport_in_content_space = gfx::ToEnclosingRect(
-        MathUtil::ProjectClippedRect(screen_to_layer, device_viewport));
+    viewport_in_content_space =
+        gfx::ToEnclosingRect(MathUtil::ProjectClippedRect(
+            screen_to_layer, gfx::Rect(viewport_size)));
   }
 
   WhichTree tree =
       layer_tree_impl()->IsActiveTree() ? ACTIVE_TREE : PENDING_TREE;
   size_t max_tiles_for_interest_area =
       layer_tree_impl()->settings().max_tiles_for_interest_area;
   tilings_->UpdateTilePriorities(
       tree,
-      layer_tree_impl()->device_viewport_size(),
+      viewport_size,
       viewport_in_content_space,
       visible_content_rect(),
       last_bounds_,
       bounds(),
       last_content_scale_,
       contents_scale_x(),
       last_screen_space_transform_,
       current_screen_space_transform,
       current_frame_time_in_seconds,
       max_tiles_for_interest_area);
@@ skipping 445 matching lines @@
       raster_contents_scale_ == 0.f ||
       low_res_raster_contents_scale_ == 0.f ||
       ShouldAdjustRasterScale(animating_transform_to_screen);
 
   // Store the value for the next time ShouldAdjustRasterScale is called.
   raster_source_scale_was_animating_ = animating_transform_to_screen;
 
   if (!change_target_tiling)
     return;
 
+  if (!layer_tree_impl()->device_viewport_valid_for_tile_management())
+    return;
+
   raster_page_scale_ = ideal_page_scale_;
   raster_device_scale_ = ideal_device_scale_;
   raster_source_scale_ = ideal_source_scale_;
 
   CalculateRasterContentsScale(animating_transform_to_screen,
                                &raster_contents_scale_,
                                &low_res_raster_contents_scale_);
 
   PictureLayerTiling* high_res = NULL;
   PictureLayerTiling* low_res = NULL;
@@ skipping 248 matching lines @@
     coverage_tiles->Append(tile_data.release());
   }
   state->Set("coverage_tiles", coverage_tiles.release());
 }
 
 size_t PictureLayerImpl::GPUMemoryUsageInBytes() const {
   return tilings_->GPUMemoryUsageInBytes();
 }
 
 }  // namespace cc