Makes browser resize content when root bounds change

Without this on android we don't open the browser to fill the screen,
nor resize when the rotation changes.

R=ben@chromium.org
BUG=none
TEST=none

Review URL: https://codereview.chromium.org/1141453002

Cr-Commit-Position: refs/heads/master@{#329289}

mandoline/ui/browser/android/android_ui.cc

@@ -5,6 +5,8 @@
 #include "mandoline/ui/browser/android/android_ui.h"
 
 #include "components/view_manager/public/cpp/view.h"
+#include "mojo/converters/geometry/geometry_type_converters.h"
+#include "ui/gfx/geometry/rect.h"
 
 namespace mandoline {
 
@@ -13,15 +15,26 @@ AndroidUI::AndroidUI(Browser* browser, mojo::Shell* shell)
       shell_(shell),
       root_(nullptr),
       content_(nullptr) {}
-AndroidUI::~AndroidUI() {}
+
+AndroidUI::~AndroidUI() {
+  root_->RemoveObserver(this);
+}
 
 void AndroidUI::Init(mojo::View* root, mojo::View* content) {
   root_ = root;
+  root_->AddObserver(this);
   content_ = content;
 
   content_->SetBounds(root_->bounds());
 }
 
+void AndroidUI::OnViewBoundsChanged(mojo::View* view,
+                                    const mojo::Rect& old_bounds,
+                                    const mojo::Rect& new_bounds) {
+  content_->SetBounds(
+      *mojo::Rect::From(gfx::Rect(0, 0, new_bounds.width, new_bounds.height)));
+}
+
 // static
 BrowserUI* BrowserUI::Create(Browser* browser, mojo::Shell* shell) {
   return new AndroidUI(browser, shell);

mandoline/ui/browser/android/android_ui.h

@@ -6,6 +6,7 @@
 #define MANDOLINE_UI_BROWSER_ANDROID_ANDROID_UI_H_
 
 #include "base/macros.h"
+#include "components/view_manager/public/cpp/view_observer.h"
 #include "mandoline/ui/browser/browser_ui.h"
 
 namespace mojo {
@@ -17,7 +18,8 @@ namespace mandoline {
 
 class Browser;
 
-class AndroidUI : public BrowserUI {
+class AndroidUI : public BrowserUI,
+                  public mojo::ViewObserver {
  public:
   AndroidUI(Browser* browser, mojo::Shell* shell);
   ~AndroidUI() override;
@@ -26,6 +28,11 @@ class AndroidUI : public BrowserUI {
   // Overridden from BrowserUI:
   void Init(mojo::View* root, mojo::View* content) override;
 
+  // Overriden from mojo::ViewObserver:
+  virtual void OnViewBoundsChanged(mojo::View* view,
+                                   const mojo::Rect& old_bounds,
+                                   const mojo::Rect& new_bounds) override;
+
   Browser* browser_;
   mojo::Shell* shell_;
   mojo::View* root_;

mandoline/ui/browser/browser.cc

@@ -31,6 +31,11 @@ base::WeakPtr<Browser> Browser::GetWeakPtr() {
   return weak_factory_.GetWeakPtr();
 }
 
+// Convenience method:
+void Browser::ReplaceContentWithURL(const mojo::String& url) {
+  Embed(url, nullptr, nullptr);
+}
+
 void Browser::Initialize(mojo::ApplicationImpl* app) {
   window_manager_app_->Initialize(app);
   ui_.reset(BrowserUI::Create(this, app->shell()));
@@ -94,6 +99,12 @@ void Browser::OnEmbed(
     Embed(default_url_, services.Pass(), exposed_services.Pass());
 }
 
+void Browser::OnViewManagerDisconnected(
+    mojo::ViewManager* view_manager) {
+  ui_.reset();
+  root_ = nullptr;
+}
+
 void Browser::Embed(const mojo::String& url,
                     mojo::InterfaceRequest<mojo::ServiceProvider> services,
                     mojo::ServiceProviderPtr exposed_services) {
@@ -125,14 +136,4 @@ void Browser::Create(mojo::ApplicationConnection* connection,
   navigator_host_.Bind(request.Pass());
 }
 
-void Browser::OnViewManagerDisconnected(
-    mojo::ViewManager* view_manager) {
-  root_ = nullptr;
-}
-
-// Convenience method:
-void Browser::ReplaceContentWithURL(const mojo::String& url) {
-  Embed(url, nullptr, nullptr);
-}
-
 }  // namespace mandoline

mandoline/ui/browser/browser.h

@@ -61,8 +61,6 @@ class Browser : public mojo::ApplicationDelegate,
   void Create(mojo::ApplicationConnection* connection,
               mojo::InterfaceRequest<mojo::NavigatorHost> request) override;
 
-  void LayoutContent();
-
   scoped_ptr<window_manager::WindowManagerApp> window_manager_app_;
 
   // Only support being embedded once, so both application-level

mandoline/ui/browser/browser_ui.h

@@ -20,6 +20,9 @@ class BrowserUI {
   static BrowserUI* Create(Browser* browser, mojo::Shell* shell);
 
   // Called when the Browser UI is embedded within the specified view.
+  // BrowserUI is destroyed prior to |root| being destroyed. That is, the
+  // BrowserUI implementations can assume |root| is never deleted out from under
+  // them.
   virtual void Init(mojo::View* root, mojo::View* content) = 0;
 };