Allow changing top controls height

cc/trees/layer_tree_host.cc

 // Copyright 2011 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/trees/layer_tree_host.h"
 
 #include <algorithm>
 #include <stack>
 #include <string>
 
@@ skipping 99 matching lines @@
       next_ui_resource_id_(1),
       inside_begin_main_frame_(false),
       needs_full_tree_sync_(true),
       client_(client),
       source_frame_number_(0),
       rendering_stats_instrumentation_(RenderingStatsInstrumentation::Create()),
       output_surface_lost_(true),
       num_failed_recreate_attempts_(0),
       settings_(settings),
       debug_state_(settings.initial_debug_state),
-      top_controls_layout_height_(0.f),
+      top_controls_shrink_blink_size_(false),
+      top_controls_height_(0.f),
       top_controls_content_offset_(0.f),
       device_scale_factor_(1.f),
       visible_(true),
       page_scale_factor_(1.f),
       min_page_scale_factor_(1.f),
       max_page_scale_factor_(1.f),
       has_gpu_rasterization_trigger_(false),
       content_is_suitable_for_gpu_rasterization_(true),
       gpu_rasterization_histogram_recorded_(false),
       background_color_(SK_ColorWHITE),
@@ skipping 232 matching lines @@
   float page_scale_delta =
       sync_tree->page_scale_delta() / sync_tree->sent_page_scale_delta();
   sync_tree->SetPageScaleValues(page_scale_factor_,
                                 min_page_scale_factor_,
                                 max_page_scale_factor_,
                                 page_scale_delta);
   sync_tree->set_sent_page_scale_delta(1.f);
 
   sync_tree->PassSwapPromises(&swap_promise_list_);
 
-  sync_tree->set_top_controls_layout_height(top_controls_layout_height_);
+  // Track the change in top controls height to offset the top_controls_delta
+  // properly.  This is so that the top controls offset will be maintained
+  // across height changes.
+  float top_controls_height_delta =
+      sync_tree->top_controls_height() - top_controls_height_;
+
+  sync_tree->set_top_controls_shrink_blink_size(
+      top_controls_shrink_blink_size_);
+  sync_tree->set_top_controls_height(top_controls_height_);
   sync_tree->set_top_controls_content_offset(top_controls_content_offset_);
   sync_tree->set_top_controls_delta(sync_tree->top_controls_delta() -
-      sync_tree->sent_top_controls_delta());
+                                    sync_tree->sent_top_controls_delta() -
+                                    top_controls_height_delta);
   sync_tree->set_sent_top_controls_delta(0.f);
 
   host_impl->SetUseGpuRasterization(UseGpuRasterization());
   RecordGpuRasterizationHistogram();
 
   host_impl->SetViewportSize(device_viewport_size_);
   host_impl->SetDeviceScaleFactor(device_scale_factor_);
   host_impl->SetDebugState(debug_state_);
   if (pending_page_scale_animation_) {
     sync_tree->SetPendingPageScaleAnimation(
@@ skipping 263 matching lines @@
 
 void LayerTreeHost::SetViewportSize(const gfx::Size& device_viewport_size) {
   if (device_viewport_size == device_viewport_size_)
     return;
 
   device_viewport_size_ = device_viewport_size;
 
   SetNeedsCommit();
 }
 
-void LayerTreeHost::SetTopControlsLayoutHeight(float height) {
-  if (top_controls_layout_height_ == height)
+void LayerTreeHost::SetTopControlsShrinkBlinkSize(bool shrink) {
+  if (top_controls_shrink_blink_size_ == shrink)
     return;
 
-  top_controls_layout_height_ = height;
+  top_controls_shrink_blink_size_ = shrink;
   SetNeedsCommit();
 }
 
+void LayerTreeHost::SetTopControlsHeight(float height) {
+  if (top_controls_height_ == height)
+    return;
+
+  top_controls_height_ = height;
+  SetNeedsCommit();
+}
+
 void LayerTreeHost::SetTopControlsContentOffset(float offset) {
   if (top_controls_content_offset_ == offset)
     return;
 
   top_controls_content_offset_ = offset;
   SetNeedsCommit();
 }
 
 void LayerTreeHost::ApplyPageScaleDeltaFromImplSide(float page_scale_delta) {
   DCHECK(CommitRequested());
@@ skipping 679 matching lines @@
     bool children_need_begin_frames) const {
   proxy_->SetChildrenNeedBeginFrames(children_need_begin_frames);
 }
 
 void LayerTreeHost::SendBeginFramesToChildren(
     const BeginFrameArgs& args) const {
   client_->SendBeginFramesToChildren(args);
 }
 
 }  // namespace cc