Fixed PDF resize issue.

This patch also introduces a test for this fix, as well as some additions to the MimeHanlderView testing infrastructure to facilitate this new test.

BUG=481104

Review URL: https://codereview.chromium.org/1113273007

Cr-Commit-Position: refs/heads/master@{#328435}

3 files changed, 18 insertions, 2 deletions

diff --git a/components/guest_view/browser/guest_view_base.h b/components/guest_view/browser/guest_view_base.h
index 04d3f41..2f167e1 100644
--- a/components/guest_view/browser/guest_view_base.h
+++ b/components/guest_view/browser/guest_view_base.h
@@ -243,6 +243,8 @@ class GuestViewBase : public content::BrowserPluginGuestDelegate,
 
   bool can_owner_receive_events() const { return !!view_instance_id_; }
 
+  gfx::Size size() const { return guest_size_; }
+
   // Returns the user browser context of the embedder.
   content::BrowserContext* browser_context() const { return browser_context_; }
 
diff --git a/components/guest_view/browser/guest_view_manager.h b/components/guest_view/browser/guest_view_manager.h
index f51d0a6..278c2cb 100644
--- a/components/guest_view/browser/guest_view_manager.h
+++ b/components/guest_view/browser/guest_view_manager.h
@@ -81,8 +81,14 @@ class GuestViewManager : public content::BrowserPluginGuestManager,
 
   template <typename T>
   void RegisterGuestViewType() {
-    auto it = guest_view_registry_.find(T::Type);
-    DCHECK(it == guest_view_registry_.end());
+    // If the GuestView type |T| is already registered, then there is nothing
+    // more to do. If an existing entry in the registry was created by this
+    // function for type |T|, then registering again would have no effect, and
+    // if it was registered elsewhere, then we do not want to overwrite it. Note
+    // that it is possible for tests to have special test factory methods
+    // registered here.
+    if (guest_view_registry_.count(T::Type))
+      return;
     guest_view_registry_[T::Type] = base::Bind(&T::Create);
   }
 
diff --git a/components/guest_view/browser/test_guest_view_manager.h b/components/guest_view/browser/test_guest_view_manager.h
index cbf942f..59964ef 100644
--- a/components/guest_view/browser/test_guest_view_manager.h
+++ b/components/guest_view/browser/test_guest_view_manager.h
@@ -32,6 +32,14 @@ class TestGuestViewManager : public GuestViewManager {
   // Returns the size of the set of removed instance IDs.
   size_t GetNumRemovedInstanceIDs() const;
 
+  using GuestViewCreateFunction =
+      base::Callback<GuestViewBase*(content::WebContents*)>;;
+
+  template <typename T>
+  void RegisterTestGuestViewType(GuestViewCreateFunction create_function) {
+    guest_view_registry_[T::Type] = create_function;
+  }
+
   // Returns the number of guests that have been created since the creation of
   // this GuestViewManager.
   int num_guests_created() const { return num_guests_created_; }