Revert "Mac: don't use a custom tracking area in BridgedContentView"

This reverts commit 7e18556b.

Reason for revert: Breaks devtools overlay: crbug.com/1090280
and link hovering: https://bugs.chromium.org/p/chromium/issues/detail?id=841792#c24

Original change's description:
> Mac: don't use a custom tracking area in BridgedContentView
> 
> Currently, in BridgedContentView we "opt out"[1] of BaseView's tracking area to install a different one which:
> - Specifies `NSTrackingCursorUpdate`
> - As a consequence, only tracks while app is active, since the docs say that always tracking is incompatible with cursor updates
> 
> However:
> - Empirically, cursor updates work fine without this (some test cases: move mouse between Omnibox and other parts of topchrome, move from webcontent links/inputs to topchrome and vice-versa).
> - Only tracking while app is active means we don't get entered/exited events from app switching. This means:
>   - Switching away from Chrome while showing a topchrome hover tooltip keeps the hover on and makes the tooltip stuck
>   - Under some circumstances, hover stops working on switching back to Chrome (see bug)
>   - Even though we allow mouse clicks to function when Chrome is inactive (that is, we return `YES` from `acceptsFirstMouse:`, we don't process hovers in this case, contrary to other apps on the system.
> 
> This change removes BridgedContentView's tracking area in favor of the default one and gives BaseView some explicit enable/disables, mostly to make tests happy.
> 
> [1] By overriding a private method with a no-op!
> 
> Bug: 841792
> 
> Change-Id: Ifb5d65e22299959b8cac25a9e0a0407650a40746
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2216530
> Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
> Reviewed-by: Avi Drissman <avi@chromium.org>
> Commit-Queue: Leonard Grey <lgrey@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#773848}

TBR=ellyjones@chromium.org,avi@chromium.org,lgrey@chromium.org

Change-Id: Ic1344adb7cdf271636026a2b1e6def014852416f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 841792, 1090280
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2223949Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774088}

components/remote_cocoa/app_shim/bridged_content_view.h

@@ -10,6 +10,7 @@
 #include "base/strings/string16.h"
 #include "components/remote_cocoa/app_shim/remote_cocoa_app_shim_export.h"
 #import "ui/base/cocoa/tool_tip_base_view.h"
+#import "ui/base/cocoa/tracking_area.h"
 
 namespace remote_cocoa {
 class NativeWidgetNSWindowBridge;
@@ -31,6 +32,9 @@ REMOTE_COCOA_APP_SHIM_EXPORT
   // Weak, reset by clearView.
   remote_cocoa::NativeWidgetNSWindowBridge* _bridge;
 
+  // A tracking area installed to enable mouseMoved events.
+  ui::ScopedCrTrackingArea _cursorTrackingArea;
+
   // The keyDown event currently being handled, nil otherwise.
   NSEvent* _keyDownEvent;
 

components/remote_cocoa/app_shim/bridged_content_view.mm

@@ -172,6 +172,17 @@ ui::TextEditCommand GetTextEditCommandForMenuAction(SEL action) {
   if ((self = [super initWithFrame:initialFrame])) {
     _bridge = bridge;
 
+    // Apple's documentation says that NSTrackingActiveAlways is incompatible
+    // with NSTrackingCursorUpdate, so use NSTrackingActiveInActiveApp.
+    _cursorTrackingArea.reset([[CrTrackingArea alloc]
+        initWithRect:NSZeroRect
+             options:NSTrackingMouseMoved | NSTrackingCursorUpdate |
+                     NSTrackingActiveInActiveApp | NSTrackingInVisibleRect |
+                     NSTrackingMouseEnteredAndExited
+               owner:self
+            userInfo:nil]);
+    [self addTrackingArea:_cursorTrackingArea.get()];
+
     // Get notified whenever Full Keyboard Access mode is changed.
     [[NSDistributedNotificationCenter defaultCenter]
         addObserver:self
@@ -216,6 +227,8 @@ ui::TextEditCommand GetTextEditCommandForMenuAction(SEL action) {
 - (void)clearView {
   _bridge = nullptr;
   [[NSDistributedNotificationCenter defaultCenter] removeObserver:self];
+  [_cursorTrackingArea.get() clearOwner];
+  [self removeTrackingArea:_cursorTrackingArea.get()];
 }
 
 - (bool)needsUpdateWindows {
@@ -532,6 +545,11 @@ ui::TextEditCommand GetTextEditCommandForMenuAction(SEL action) {
 
 // BaseView implementation.
 
+// Don't use tracking areas from BaseView. BridgedContentView's tracks
+// NSTrackingCursorUpdate and Apple's documentation suggests it's incompatible.
+- (void)enableTracking {
+}
+
 // Translates the location of |theEvent| to toolkit-views coordinates and passes
 // the event to NativeWidgetMac for handling.
 - (void)mouseEvent:(NSEvent*)theEvent {

ui/base/cocoa/base_view.mm

@@ -12,23 +12,29 @@ NSString* kSelectionDirection = @"Chromium.kSelectionDirection";
 
 @implementation BaseView
 
-
-- (void)dealloc {
-  [self disableTracking];
-  [super dealloc];
+- (instancetype)initWithFrame:(NSRect)frame {
+  if ((self = [super initWithFrame:frame])) {
+    [self enableTracking];
+  }
+  return self;
 }
 
-- (void)viewWillMoveToWindow:(NSWindow*)window {
-  if (window) {
+- (instancetype)initWithCoder:(NSCoder*)decoder {
+  if ((self = [super initWithCoder:decoder])) {
     [self enableTracking];
-  } else {
-    [self disableTracking];
   }
+  return self;
+}
+
+- (void)dealloc {
+  [self disableTracking];
+  [super dealloc];
 }
 
 - (void)enableTracking {
   if (_trackingArea.get())
     return;
+
   NSTrackingAreaOptions trackingOptions = NSTrackingMouseEnteredAndExited |
                                           NSTrackingMouseMoved |
                                           NSTrackingActiveAlways |