Add a content_settings::BaseProvider for code that is shared by all content settings providers.

chrome/browser/content_settings/content_settings_provider.h

Index: chrome/browser/content_settings/content_settings_provider.h
diff --git a/chrome/browser/content_settings/content_settings_provider.h b/chrome/browser/content_settings/content_settings_provider.h
index 621c5222888982b7b6a3aa91c62d26498a0be622..98d458fbdf16cc2247abcbfa900a6b69c6044b0f 100644
--- a/chrome/browser/content_settings/content_settings_provider.h
+++ b/chrome/browser/content_settings/content_settings_provider.h
@@ -8,9 +8,12 @@
 #define CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_PROVIDER_H_
 #pragma once
 
+#include <map>
 #include <string>
+#include <utility>
 #include <vector>
 
+#include "base/synchronization/lock.h"
 #include "chrome/browser/content_settings/content_settings_pattern.h"
 #include "chrome/common/content_settings.h"
 
@@ -119,6 +122,113 @@ class ProviderInterface {
   virtual void ResetToDefaults() = 0;
 };
 
+typedef std::pair<ContentSettingsType, std::string>
+    ContentSettingsTypeResourceIdentifierPair;
+typedef std::map<ContentSettingsTypeResourceIdentifierPair, ContentSetting>
+    ResourceContentSettings;
+
+struct ExtendedContentSettings {
+  ContentSettings content_settings;
+  ResourceContentSettings content_settings_for_resources;
+};
+
+// Map for ContentSettings.
+typedef std::map<std::string, ExtendedContentSettings> HostContentSettings;
+
+// BaseProvider is the abstract base class for all PolicyProvider classes.

[Bernhard Bauer, 2011/02/14 16:58:36]

Nit: and also for PrefProviders?

[markusheintz_, 2011/02/14 18:25:28]

Done.

+class BaseProvider : public ProviderInterface {

[Bernhard Bauer, 2011/02/14 16:58:36]

With this class and ProviderUtil below, this file will declare four classes,
none of which have a name that corresponds to the filename. That makes searching
for classes really difficult. I'd propose the following: 

- Only subclasses of BaseProvider need to know about it, so you could move it
out to separate header/implementation files.
- A class named namespace::ClassName should live in namespace_class_name.*
files, so in this case you should have all filenames start with
content_settings_, like content_settings_base_provider,
content_settings_pref_provider, etc.
- If a header file defines multiple classes, we usually use a plural name for it
(*Value classes are defined in values.h), so you could rename this file
content_settings_providers.h.

[markusheintz_, 2011/02/14 18:25:28]

You are right this file grew into a real beast now. I'll cut off a couple of
heads.

- I'll move BaseProvider to base_provider.[h,cc] incl. the typedefs

- It's likely that DefaultProviderInterface will go away r merged again in
ProviderInterface. So I'd like to keep these two classes in the same file
content_settings_provider.h and not rename it. Would you be fine with me adding
a comment that this is work in progress?

- The method in ProviderUtil could become a static method of BaseProvider. It's
so tiny and does not deserve a file on it's own yet. And ProviderUtil can go
away again.

wdyt

+ public:
+  explicit BaseProvider(bool is_otr)
+      : is_off_the_record_(is_otr) {
+  }
+  virtual ~BaseProvider() {}
+
+  // Initializes the Provider.
+  virtual void Init() = 0;
+
+  // ProviderInterface Implementation
+  virtual bool ContentSettingsTypeIsManaged(
+      ContentSettingsType content_type) = 0;
+
+  virtual ContentSetting GetContentSetting(
+      const GURL& requesting_url,
+      const GURL& embedding_url,
+      ContentSettingsType content_type,
+      const ResourceIdentifier& resource_identifier) const;
+
+  virtual void SetContentSetting(
+      const ContentSettingsPattern& requesting_pattern,
+      const ContentSettingsPattern& embedding_pattern,
+      ContentSettingsType content_type,
+      const ResourceIdentifier& resource_identifier,
+      ContentSetting content_setting) = 0;
+
+  virtual void GetAllContentSettingsRules(
+      ContentSettingsType content_type,
+      const ResourceIdentifier& resource_identifier,
+      Rules* content_setting_rules) const;
+
+  virtual void ClearAllContentSettingsRules(
+      ContentSettingsType content_type) = 0;
+
+  virtual void ResetToDefaults() = 0;
+
+ protected:
+  // Returns true if the |content_type| requires a resource identifier.
+  bool RequiresResourceIdentifier(
+      ContentSettingsType content_type) const;
+
+  // Returns true if the passed |settings| object contains only
+  // CONTENT_SETTING_DEFAULT values.
+  bool AllDefault(const ExtendedContentSettings& settings) const;
+
+  // TODO(markusheintz): LEGACY method. Will be removed in a futur re-factoring

[Bernhard Bauer, 2011/02/14 16:58:36]

Nit: "future"

[markusheintz_, 2011/02/14 18:25:28]

Done.

+  // step.
+  ContentSettings GetNonDefaultContentSettings(const GURL& url) const;
+
+  // Accessors
+  HostContentSettings* host_content_settings() {
+    return &host_content_settings_;
+  }
+
+  HostContentSettings* off_the_record_settings() {
+    return &off_the_record_settings_;
+  }
+
+  base::Lock& lock() const {
+    return lock_;
+  }
+
+  bool is_off_the_record() const {
+    return is_off_the_record_;
+  }
+
+ private:
+  // Copies of the pref data, so that we can read it on threads other than the
+  // UI thread.
+  HostContentSettings host_content_settings_;
+
+  // Whether this settings map is for an OTR session.
+  bool is_off_the_record_;
+
+  // Differences to the preference-stored host content settings for
+  // off-the-record settings.
+  HostContentSettings off_the_record_settings_;
+
+  // Used around accesses to the content_settings_ object to guarantee
+  // thread safety.
+  mutable base::Lock lock_;
+};
+
+// ProviderUtil provides utility methods for content-settings-providers.
+class ProviderUtil {
+ public:
+  // Maps CONTENT_SETTING_ASK for the CONTENT_SETTINGS_TYPE_PLUGINS to
+  // CONTENT_SETTING_BLOCK if click-to-play is not enabled.
+  static ContentSetting ClickToPlayFixup(ContentSettingsType content_type,
+                                         ContentSetting setting);
+};
+
 }  // namespace content_settings
 
 #endif  // CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_PROVIDER_H_