Implement Just-In-Time Flash updates.

components/component_updater/component_updater_service.h

Index: components/component_updater/component_updater_service.h
diff --git a/components/component_updater/component_updater_service.h b/components/component_updater/component_updater_service.h
index 7abf4d6bc955908e802777df0a2874d5e9863a19..c257ae499a5981adf4f943102206572586ad3ab9 100644
--- a/components/component_updater/component_updater_service.h
+++ b/components/component_updater/component_updater_service.h
@@ -19,6 +19,7 @@
 #include "url/gurl.h"
 
 class ComponentsUI;
+class PluginObserver;
 class SupervisedUserWhitelistService;
 
 namespace base {
@@ -51,6 +52,14 @@ using Configurator = update_client::Configurator;
 using CrxComponent = update_client::CrxComponent;
 using CrxUpdateItem = update_client::CrxUpdateItem;
 
+struct ComponentInfo {
+  ComponentInfo();
+  ~ComponentInfo();
+
+  std::string id;
+  base::string16 name;
+};
+
 // The component update service is in charge of installing or upgrading
 // select parts of chrome. Each part is called a component and managed by
 // instances of CrxComponent registered using RegisterComponent(). On the
@@ -96,6 +105,14 @@ class ComponentUpdateService {
   // Returns a list of registered components.
   virtual std::vector<std::string> GetComponentIDs() const = 0;
 
+  // Returns true and fills the members of |info| if there is a registered
+  // component that implements a handler for the specified |mime_type|; else
+  // returns false and does not mutate the members of |info|. If multiple
+  // such components exist, returns information for the one that was most
+  // recently registered.
+  virtual bool GetComponentForMimeType(const std::string& mime_type,
+                                       ComponentInfo* info) const = 0;

[Sorin Jianu, 2016/07/28 21:04:05]

Another idea for this would be to return by value an
std::unique_ptr<ComponentInfo> or nullptr instead of bool and the comment about
not mutating |info|.

[waffles, 2016/07/28 23:05:52]

Done.

+
   // Returns an interface for on-demand updates. On-demand updates are
   // proactively triggered outside the normal component update service schedule.
   virtual OnDemandUpdater& GetOnDemandUpdater() = 0;
@@ -140,6 +157,7 @@ class OnDemandUpdater {
   friend class OnDemandTester;
   friend class SupervisedUserWhitelistInstaller;
   friend class ::ComponentsUI;
+  friend class ::PluginObserver;
 
   // Triggers an update check for a component. |id| is a value
   // returned by GetCrxComponentID(). If an update for this component is already