Allow setting different hit test bounds overrides for mouse and touch

ash/wm/frame_border_hit_test_controller.cc

Index: ash/wm/frame_border_hit_test_controller.cc
diff --git a/ash/wm/frame_border_hit_test_controller.cc b/ash/wm/frame_border_hit_test_controller.cc
index 28a572667153287db52c5356c6cd1f99f2cb16bc..b1e427cce4b023d128c5325f392b5f4243f43a66 100644
--- a/ash/wm/frame_border_hit_test_controller.cc
+++ b/ash/wm/frame_border_hit_test_controller.cc
@@ -14,6 +14,17 @@
 #include "ui/views/widget/widget_delegate.h"
 #include "ui/views/window/non_client_view.h"
 
+namespace {
+
+// The height of the region in |frame_window_| where |frame_window_| should grab
+// touches while in immersive fullscreen. (Even if a child window overlaps this
+// region.) This region is used to allow us to intercept edge gestures to
+// reveal the top-of-window views even if |frame_window_|'s web page conumes all
+// touch events.
+const int kImmersiveFullscreenTopInnerInsetTouch = 8;
+
+}  // namespace
+
 namespace ash {
 
 FrameBorderHitTestController::FrameBorderHitTestController(views::Widget* frame)
@@ -82,15 +93,29 @@ int FrameBorderHitTestController::NonClientHitTest(
 }
 
 void FrameBorderHitTestController::UpdateHitTestBoundsOverrideInner() {
-  // Maximized and fullscreen windows don't want resize handles overlapping the
-  // content area, because when the user moves the cursor to the right screen
-  // edge we want them to be able to hit the scroll bar.
-  if (wm::GetWindowState(frame_window_)->IsMaximizedOrFullscreen()) {
-    frame_window_->set_hit_test_bounds_override_inner(gfx::Insets());
+  wm::WindowState* window_state(wm::GetWindowState(frame_window_));
+  if (window_state->IsFullscreen()) {
+    // Fullscreen windows don't want resize handles when the mouse is on top of
+    // the content area, so it is unnecessary to steal events from the web
+    // contents along |frame_window_|'s edges. While in immersive fullscreen, we
+    // grab touch events along the top edge of |frame_window_| so that we can
+    // intercept edge gestures to reveal the top-of-window views even if the
+    // web contents consumes all touch events.
+    if (window_state->IsImmersiveFullscreen()) {
+      frame_window_->SetHitTestBoundsOverrideInner(gfx::Insets(),
+          gfx::Insets(kImmersiveFullscreenTopInnerInsetTouch, 0, 0, 0));
+    } else {
+      frame_window_->SetHitTestBoundsOverrideInner(gfx::Insets(),
+                                                   gfx::Insets());
+    }
+  } else if (window_state->IsMaximized()) {
+    // We do not want resize handles for maximized windows either.
+    frame_window_->SetHitTestBoundsOverrideInner(gfx::Insets(),
+                                                 gfx::Insets());
   } else {
-    frame_window_->set_hit_test_bounds_override_inner(
-        gfx::Insets(kResizeInsideBoundsSize, kResizeInsideBoundsSize,
-                    kResizeInsideBoundsSize, kResizeInsideBoundsSize));
+    gfx::Insets insets(kResizeInsideBoundsSize, kResizeInsideBoundsSize,
+                       kResizeInsideBoundsSize, kResizeInsideBoundsSize);
+    frame_window_->SetHitTestBoundsOverrideInner(insets, insets);
   }
 }
 
@@ -100,6 +125,12 @@ void FrameBorderHitTestController::OnWindowShowTypeChanged(
   UpdateHitTestBoundsOverrideInner();
 }
 
+void FrameBorderHitTestController::OnWindowFullscreenTypeChanged(
+    wm::WindowState* window_state,
+    wm::FullscreenType old_type) {
+  UpdateHitTestBoundsOverrideInner();
+}
+
 void FrameBorderHitTestController::OnWindowDestroying(aura::Window* window) {
   frame_window_->RemoveObserver(this);
   ash::wm::GetWindowState(frame_window_)->RemoveObserver(this);